British Foreign Secretary Philip Hammond said on Tuesday that the four year benefits ban on migrant workers from other European Union member countries is flexible.
"There is no magic about four years," Hammond said. "It is just a figure that we calculated would provide a sufficient deterrent.”
"If someone was to say it has to be less than four years, they would have to show there is a compensating mechanism that would mean it would have the same effect on migration," he continued.
Hammond said that the main goal is to reduce migration and tell the EU that Brussel’s power on London has crossed the high water mark.
“For most people in this country, the EU has too much power; they probably would like to see a bit of power coming back to the nation state.”
He has recently visited all 27 EU capitals to discuss Britain’s demands from the union.
“Everyone gets what we need and everyone gets what we are trying to do. Some are sympathetic and some are not,” he said, referring to the in-out referendum on the country's EU membership.
In February, there will be an EU summit on Britain’s membership, and the UK will have a referendum on "Brexit" in 2017, although commentators widely believe it might happen this year.
Hammond said a treaty change with EU is necessary for at least some of the changes London wants.
“We know we cannot have it before the referendum; that is impossible, but what we can have is a legally binding agreement to incorporate the changes we need at the next opening of the treaties,” he said.
Prime Minister David Cameron hopes to strike a deal with Brussels at the EU summit, before campaigning to stay in the union.
Regional and local elections will be held in May, and Cameron wants a referendum campaign lasting at least three months.
Hammond said a referendum before September is “very tight,” rejecting the claims that it could take place between July and August.