A top European Commission official says difficult issues still remain to be resolved before the EU and Britain strike a deal in February.
"We have only a few weeks left. There are still difficult issues remaining to be resolved," Jonathan Faull, head of the British referendum task force at the Brussels-based Commission told a European Parliament committee when asked to rate the chances of a deal.
Faull said that very intensive discussions are likely to resolve the remaining issues on Britain's demands to stay in the 28-nation bloc.
“Both sides have shown political will to reach an agreement at the upcoming summit”, he said while assessing the possibilities of a deal with Britain at a European Parliament committee.
He added that Commission was "working to keep the UK in the EU because we believe it's in the interest of the EU, and without interfering in any way, we believe it's in the interest of the UK."
British Prime Minister David Cameron has said that he is reasonably confident of an accord ahead of a referendum planned in mid-2016 on a possible “Brexit”.
London has demanded reforms in several areas, the most controversial being a four-year ban on top-up benefits for EU nationals working in Britain.
There is less opposition to other demands which got backing from some countries during Cameron’s recent trip to European nations. During his visit to Germany earlier this month, Cameron argued that London's proposals would benefit the bloc and the UK both.
But critics say the issue related to EU migrants is discriminatory and threatens freedom of movement in the EU.
‘Brexit impact’
Meanwhile, European Commission economists have been asked not to review or talk about the impact of a possible exit of Britain from the bloc.
"There is an internal order not to discuss or study the impact of Brexit," a senior Commission official told Reuters, adding that the instruction had come from the office of European Union chief executive Jean-Claude Juncker.
Another senior EU official said that the Commission had learned to its cost the consequences of such contingency planning last year. He said Grexit - the risk of Greece leaving the eurozone was a reason to ask researchers not to even talk about Brexit.
The 43-year EU membership has long been a contentious topic in Britain. Pro-Europeans warn the move would not only hurt the economy but could possibly trigger the break-up of the kingdom by prompting another Scottish independence vote.
Opponents of EU membership say Britain would prosper outside the bloc. A number of recent opinion polls have suggested that a growing number of Britons now favor the break up from the EU.
The costs and benefits of EU membership for the British economy will be a key issue in the referendum campaign.