LONDON (Reuters) - British Prime Minister Boris Johnson wrote to all government employees on Friday to tell them that preparing for a no-deal exit from the European Union is his and their top priority, according to a copy of the email seen by Reuters.

Britain's Prime Minister Boris Johnson visits the Fusion Energy Research Centre at the Fulham Science Centre in Oxfordshire, Britain August 8, 2019. Julian Simmonds/Pool via REUTERS

Johnson has promised voters Britain will leave the EU on Oct. 31 with or without an exit deal, demanding that Brussels drop parts of the existing proposed deal relating to the Irish border and negotiate a fresh exit arrangement.

But the EU is adamant that the legal terms of the deal cannot be rewritten, raising expectations among politicians and financial markets that Britain is headed for an unmanaged divorce from the bloc in less than three months’ time.

“I would very much prefer to leave with a deal – one that must abolish the anti-democratic Irish backstop, which has unacceptable consequences for our country,” Johnson said in the email.

“But I recognise this may not happen. That is why preparing urgently and rapidly for the possibility of an exit without a deal will be my top priority, and it will be the top priority for the Civil Service too.”

Previously, pro-Brexit campaigners have criticised the ranks of Britain’s civil service, which adopts a politically neutral stance while working to enact government policy, saying they were biased towards remaining in the EU and trying to obstruct the exit process.

Many investors say a no-deal Brexit would send shock waves through the world economy, tip Britain into a recession, roil financial markets and weaken London’s position as the pre-eminent international financial centre.

“I know many of you have already done a great deal of hard work in mobilising to prepare for a No Deal scenario, so that we can leave on 31 October come what may,” Johnson wrote in the email, first reported by Sky News.

“Between now and then, we must engage and communicate clearly with the British people about what our plans for taking back control mean, what people and businesses need to do, and the support we will provide.”

Although advocates of a no-deal exit say that Britain would swiftly recover from any disruption and benefit over the long term from improved economic flexibility, sterling and other economic indicators reflect a broadly pessimistic outlook.

Data on Friday showed the British economy shrank unexpectedly for the first time since 2012 in the second quarter, dragged down by a slump in manufacturing.

Johnson, however praised the work of government employees in the 650-word bulletin issued on Friday afternoon, and promised a reforming agenda beyond Brexit, highlighting plans for improved public services.

“The Government I lead is fully committed to leaving the European Union by 31 October 2019 and getting a grip of the vital issues that affect people’s lives: the NHS, education and crime,” he wrote.

“While there are no grounds for complacency, there is every reason for optimism.”