LONDON (Reuters) - British Prime Minister Theresa May said on Friday that a Brexit transition period will be agreed with the European Union in seven weeks as she tries to ease concerns that a deal may take longer to reach.

British Prime Minister Theresa May speaks at the China-UK business forum in Shanghai, China February 2, 2018. REUTERS/Stringer

The EU has offered Britain a status quo transition until the end of 2020 after Brexit. Both sides are aiming to reach a transition agreement by the end of March that will form part of the final withdrawal treaty to be agreed later this year.

But there is disagreement inside May’s Conservative Party over some details such as the status of EU citizens during the transition and the scope of European Court of Justice jurisdiction.

Many businesses and banks are concerned a battle over the terms of a transition could delay or even sink an agreement just months before Britain exits the EU on March 29, 2019.

“In seven weeks time, we will have an agreement with the European Union, that is the timetable they have said on an implementation period,” May told the BBC in an interview in China.

“What the British people voted for is for us to take back control of our money, our borders and our laws and that’s exactly what we are going to do,” May said of Brexit.

The EU and Britain hope to hammer out a deal on Britain’s exit and the outline of a trade package by October 2018.

But some EU officials have begun to voice concern that a plan to have the leaders endorse negotiating guidelines for a new phase of talks to begin in April on a future trade agreement may be in danger of slipping if May does not spell out what Britain’s demands are for that trade pact.

Once May does so, the EU will need some weeks to prepare its own negotiating proposals. Once adopted by leaders in March, negotiations could then begin with a few weeks.

However, if the March deadline is missed, there would be a risk of waiting until the next full EU summit, which is not planned until late June, creating a very tight deadline to agree a broad political declaration of future trade plans.

“We still expect to be able to have the trade guidelines for the March summit,” one senior EU official said. “But Theresa May is being so discreet. If she doesn’t say what she wants, we may not be able to prepare our position in time.”