UK Prime Minister David Cameron expressed his pleasure on Monday over a last-minute deal between Greece and its EU creditors in Brussels, after 17 hours negotiations.

Cameron added, however, that more needs to be done. “Obviously the challenge now is fulfilling the program and implementing what lies ahead -and I think we should not underestimate to scale of this challenge”, he said.

Cameron’s government has announced that it will hold a referendum, possibly in 2016, on whether the United Kingdom will remain in the EU or not.