Brexit: Why falling pound could cost Arsenal millions
Premier League stars demand huge pay rises to compensate for collapse of pound since EU referendum
EU referendum: How Brexit could affect British football
Hundreds of footballers could lose the right to play in the UK if Britain votes to leave the European Union, it has been claimed.
Under current rules, players with an EU passport are free to play in the UK while those without must meet strict Home Office criteria to get a work visa.
However, according to a study by the BBC, 332 European players currently playing in the Premier League, Championship and Scottish Premiership would fail to meet the non-EU criteria if the UK broke away from the bloc.
"More than 100 Premier League players would be affected with Aston Villa, Newcastle United and Watford facing losing 11 players from their squads, while Championship side Charlton Athletic would need to find 13 replacements," says the corporation.
"Only 23 of the 180 non-British EU players currently playing in the Championship would get work permits... Remarkably, none of the 53 non-British EU players in the Scottish Premiership would qualify for a permit on the basis of their international career alone."
A further 109 players in Leagues One and Two would also suffer.
"Leaving the EU will have a much bigger effect on football than people think," football agent Rachel Anderson told the BBC. "We're talking about half of the Premier League needing work permits."
The FA and Premier League admit they have no idea what would be the effect of Brexit. It could lead to quotas or trade deals with South American countries, says the BBC. There could also be a benefit for home-grown British players, who would find themselves in demand at big clubs.
Under current rules, players including N'Golo Kante of Leicester City and Dimitri Payet of West Ham United would be in danger. Last year, The Guardian warned that the likes of Francis Coquelin, David de Gea and Juan Mata would also struggle to get work permits under the existing guidelines.
EU referendum: would Brexit destroy the Premier League?
Britain's future in the European Union has dominated the headlines since David Cameron announced that his promised referendum on the issue would be held on Thursday 23 June.
But while politicians and business leaders have nailed their colours to the mast, there has been relatively little comment from the world of sport - and in particular the Premier League, which relies on Europe for much of its attraction.
So how would Brexit affect football in the UK?
Restrictions on foreign players
The most obvious impact will be on players. At present, all EU nationals are free to play in the Premier League and other divisions while those from beyond its borders must obtain permission. If Britain leaves the EU, there are fears it will become much harder for European players to come to England.
Under current FA rules, non-EU players must play a certain number of internationals to gain a visa. The rules also take Fifa rankings and the transfer fee into account.
If those rules were applied to all foreign players, many EU stars in the Premier League would not qualify. Last year, a study by The Guardian found that "two thirds [of European players] would not have met the criteria currently used for non-Europeans".
Among those the paper says could be affected are Chelsea's Kurt Zouma and Cesar Azpilicueta; Hector Bellerin and Francis Coquelin of Arsenal; David de Gea, Juan Mata, Morgan Schneiderlin and Anthony Martial of Manchester United, and Manchester City's Eliaquim Mangala, Jesus Navas and Samir Nasri.
"Cutting ourselves off from Europe would have devastating consequences," warned Karren Brady, chairman of West Ham United, in a letter to Premier League clubs earlier this year. "Losing this unhindered access to European talent would put British clubs at a disadvantage compared to continental sides."
The Guardian also points out that the impact would be even more keenly felt in the lower divisions, where overseas players are of a lower standard. But it accepts that the rules are unlikely to be applied retrospectively.
No more loopholes
Membership of the EU also offers loopholes for players from farther afield. Many South American players have been able to claim Spanish citizenship and then move to the Premier League. Brazil-born Diego Costa is one example.
There are others, too. Arsenal players Joel Campbell of Costa Rica and Carlos Vela of Mexico did not qualify for work permits when they arrived in England as teenagers but were farmed out to clubs in EU countries with less stringent immigration laws and became eligible to play in the Premier League after breaking into their national sides.
Can't a special deal be struck with Europe?
Maybe, but the Premier League won't have it all their own way.
"I don't think the same standards would be applied to players from the EU as they currently are to non-EU players," said Daniel Geey, a partner at sports and media law firm Sheridans, telling The Independent: "Arranging bilateral regulations for footballers won't be the first thing on governments' minds."
This could also become a hot potato domestically as the issue of work permits will give the Football Association "welcome leverage over the Premier League", says the paper. "The FA could also limit foreign players to, for example, five per team in the FA Cup – without having to adopt the fudge that allows players such as Cesc Fabregas to qualify as 'home-grown'."
But that might have unexpected consequences, says The Guardian. "In this scenario it could become difficult to justify one rule for football clubs and a different rule for other industries. It would also raise questions as to whether it would be discriminatory to establish one set of rules for Europeans and another for footballers from the rest of the world."
So, could it level the playing field?
Rather than making it harder for players, could Britain leaving the EU lead to a relaxation on the rules? That is the hope of Brian Monteith of the Leave.eu campaign.
"The freedom of movement for people in the EU comes at the price of heavy restrictions on visas for potential signings from Africa, the Caribbean, South America and Asia," he told the BBC. "Once we leave the EU, the UK will be free to treat footballers from all countries equally, which will broaden the pool of talent for our teams, not reduce it."
The FA vs the Premier League
Brexit would highlight differences between the FA and Premier League, Rory Miller, who taught a "football industries" MBA at Liverpool University, told the BBC.
"The interests of the FA, which is concerned about the future of the England team, and the Premier League, which is concerned with maximising the value of national and international broadcasting rights for the clubs, are far from identical," he said.
"The worst case scenario for the Premier League is that it would not be permitted to attract foreign stars in great numbers and would then lose ground in international sponsorship and broadcasting rights to rivals like Spain and Germany."
He also warned that "isolationism" could affect the standard of football in the Premier League. Russian clubs, which have been forced to field quotas of domestic players, believe their competition and the national team have suffered as a result.
Speaking at the annual convention of the Institute of Directors last year, Richard Scudamore, the chairman of the Premier League, said the UK should stay in Europe "from a business perspective", but made it clear he opposed any creation of a single market for television rights.
A free movement of goods – that is, players - was important, he said, but it was also important to have "audiovisual... territorialism" to safeguard the Premier League's revenue.
Premier League television rights in the UK sold for £5.1bn last year and there are separate deals in place across Europe.
What about the fans?
Supporters are often overlooked in debates about football and they, too, could pay a price if Britain leaves the EU. In her letter, Karren Brady pointed out that fans travelling to away games in Europe currently enjoy cheaper flights and do not require visas.
That could change with Brexit, while the fall in the value of the pound that is expected to follow would make travelling overseas to watch games become more expensive.
The impact on foreign investment
It's an unlikely scenario but the imposition of exchange controls could "hinder foreign owners and big cross-border transfers", says The Independent. However, a post-Brexit UK "would probably be encouraging overseas investment, not blocking it", it adds.
But the paper points out that if the Premier League is shorn of many of its overseas stars, it may become a less attractive option to overseas investors.