London: British Prime Minister David Cameron said on Monday that renegotiating Britain’s relationship with the European Union would be tough but that his decisive election victory last week had given him a mandate.

“We have got a mandate, it will be tough obviously but we have got a mandate,” Cameron told reporters before addressing a meeting of his lawmakers in parliament to loud applause and cheers, the first such meeting since his election victory.

Cameron, who won a surprise outright majority last week, has promised to renegotiate Britain’s EU ties before holding an in-out EU membership referendum by the end of 2017.

The issue of Europe is one that has split his party before and led to the downfall of two of his predecessors, Margaret Thatcher and John Major, and Cameron is keen to ensure that some of his most Eurosceptic lawmakers do not rebel.

Since being re-elected, Cameron has phoned some European leaders to discuss the planned British renegotiation, which he has said will get underway soon.

He received a boost on Monday morning when former European Commission president Jose Manuel Barroso said Cameron was in a stronger position to reshape Britain’s ties after being re-elected and that the bloc would give him some of what he wants.