British Prime Minister Theresa May has informed Parliament that she is taking personal control of European Union withdrawal negotiations, with new Brexit Secretary Dominic Raab "deputising" for her in talks.

The Europe Unit, led by Olly Robbins in the Cabinet Office, which reports directly to the Prime Minister, will have "overall responsibility for the preparation and conduct of the negotiations", drawing on support from Mr Raab's Department for Exiting the EU, she said.

In a written statement to the Commons, Mrs May spelt out how the change to operations will work.

"DExEU will continue to lead on all of the government's preparations for Brexit: domestic preparations in both a deal and a no-deal scenario, all of the necessary legislation, and preparations for the negotiations to implement the detail of the Future Framework.

"I will lead the negotiations with the European Union, with the Secretary of State for Exiting the European Union deputising on my behalf.

"Both of us will be supported by the Cabinet Office Europe Unit and with this in mind the Europe Unit will have overall responsibility for the preparation and conduct of the negotiations, drawing upon support from DExEU and other departments as required.

Mrs May said that DExEU will recruit some new staff to work on preparations for Brexit, while a number of Cabinet Office officials will move over to the department.

There will be no net reduction to staff numbers in Mr Raab's department, she said.

Raab publishes EU (Withdrawal Agreement) Bill

Meanwhile, the British government has published details of the legislation it plans to use to implement the withdrawal agreement taking the UK out of the EU next March.

Unveiling the plans in a white paper in the House of Commons, Brexit Secretary Dominic Raab described it as "another key milestone in the UK's path to leaving the EU".

And he repeated his warning that the UK could withhold payment of its £39 billion "divorce bill" if the EU fails to reach agreement on its future trade relationship with the UK.

"There must be a firm commitment in the withdrawal agreement requiring the framework for the future relationship to be translated into legal text as soon as possible," Mr Raab told MPs.

"It is one part of the whole deal we are doing with our EU partners.

"And of course if one party fails to honour its side of that overall bargain, there will be consequences for the deal as a whole - and that includes the financial settlement."

The 38-page white paper sets out plans for an EU (Withdrawal Agreement) Bill to be brought forward after Parliament has approved a deal reached during ongoing negotiations in Brussels, to ensure its implementation in time for the 29 March 2019 date of Brexit.

Initially announced last November, the Bill will create a new financial authority to manage payments to the EU over the years after Brexit.

Mr Raab repeated the British government's intention to finalise the withdrawal agreement, as well as a political declaration on future UK-EU relations, in October. This would allow for the new Bill to pass through Parliament in late 2018 and early 2019.

It covers issues including the rights of EU citizens in the UK and Britons living in the remaining 27 member states, the financial settlement and the details of a transition period expected to end in December 2020. Precise details will not be known until the withdrawal agreement is concluded.

Mr Raab said the publication of the white paper will allow "maximum scrutiny" of the government's plans by Parliament.

"By publishing the white paper today, the government is providing further certainty to people, to businesses, here in the UK and indeed across the EU," he told MPs.

"It also sends a clear signal to the European Union that the United Kingdom is a reliable, dependable negotiating partner, delivering on the commitments it has made across the negotiation table."

Reporting: PA/Reuters