Limiting EU migrants’ benefits is likely to be the biggest sticking point in Mr Cameron’s negotiations with his fellow European leaders, as it runs against the Brussels’ anti-discrimination laws.
It has been suggested the only way for the Government to work around fundamental EU legislation would be to also apply the benefit ban to British workers.
Tomas Prouza, the Czech Republic’s secretary of state for European affairs, described such an arrangement the “only solution” to Mr Cameron achieving his key demand.
He told the Daily Telegraph: “Reforms to the social system should apply to everybody.
“If you haven’t lived in the UK for a number of years, for example, and you are a British citizen or a Czech citizen the same rules should apply.
“I think that’s the only solution because non-discrimination of EU citizens is a basis of the permanent treaties and I don’t think there is any other way around this.”
The two leaders visited the Bulgaria/Turkey border
MEP David McAllister, who represents Chancellor Merkel’s CDU party in the European Parliament, described the issue as “highly problematic” as he warned any deal could be struck down by EU judges.
He told BBC Radio 4’s Today programme: “Some of the issues, I think, are rather easy. Others are more difficult, especially the questions of migration.
“The proposal for a four-year qualification period for in-work benefits is highly problematic for the other member states, because it touches upon the fundamental freedoms of our internal market.
“The treaty is crystal clear – direct discrimination between EU citizens is contrary to the rules.
“The rules for the single market apply for all 28 member states and the single market is about goods, services and capital, but it’s also about people.
“It will be a lot about how we can put this in detail to make it work within the treaty framework.
“There’s no use passing some legislation and then the European Court of Justice repealing it later on.”
I think the best thing we could do in the UK is to vote ‘Leave’ and act as a catalyst for the really big change that the EU needs to make to itself.
Bernard Jenkin, Conservative MP for Harwich and North Essex, suggested the Prime Minister’s reforms were so weak that EU leaders can’t be bothered to deal with his “pretty trivial but extremely complicated” demands.
He told the programme: “Our European partners simply haven’t got the patience to deal with this when there is so much else on their agenda.
“They’ve got massive unemployment in parts of Europe, the eurozone is teetering on the brink of crisis all the time and now we’ve got this terrible migration crisis and the Paris attacks and the aftermath of that to deal with.
“I think they are pretty exasperated because they still don’t really understand what David Cameron is really asking for.”
He added: “I think the best thing we could do in the UK is to vote ‘Leave’ and act as a catalyst for the really big change that the EU needs to make to itself.”