Theresa May is ruining Brexit by putting the Conservatives before national interest, says former top civil servant

Policy team went back to drawing board after losing majority in election

Ms May's Government scrambled for a plan after David Cameron said there was no need for one before EU referendum (PA)

Theresa May is “staring into the abyss” of Brexit by placing party over national interest, former senior civil servants have claimed.

Between the EU referendum and the UK general election this June, government officials have stalled Brexit negotiations and have been forced to go back to the policy drawing board after the Conservatives lost their parliamentary majority.

Nicholas Macpherson, a crossbench peer and former head of the Treasury, told the Financial Times: “All too frequently in the last year the national interest has been subordinated to party interest.”

He added that although there had been some progress, there was an “absence of realism”.

“Historically, Britain has always stared into the abyss, only to pull back,” he said. “My hope is that someone will get a grip before it’s too late.”

John Kerr, a crossbench peer and former head of the Foreign Office, also told the newspaper: “It has been a completely wasted year while the Tories negotiated with themselves.”

The comments come after Ms May adopted the slogan of “no deal is better than a bad deal”, which Chancellor of the Exchequer Philip Hammond tried to justify by comparing Brexit to buying a house (”you don’t move all your furniture in on the first day you buy it”) and Foreign Secretary Boris Johnson was criticised for claiming EU leaders can “go whistle” over the divorce bill.

The party is still reeling after its shock plunge in the polls before the election and the narrow victory on 8 June, resulting in giving around £1.5bn for the DUP to prop up a minority government in Westminster.

Some politicians have called for a parliamentary inquiry into the failings of the first year after Brexit, and have been keen to blame former co-chiefs of staff, Nick Timothy and Fiona Hill, who reportedly had significant influence over Brexit decisions and who resigned promptly after the election.

Ministers have also reportedly complained about a lack of discussion at the 2016 party conference to trigger Article 50, or the “red line” promise to end the European Court of Justice jurisdiction in the UK, and have called for more transparency outside of the inner circle.

Downing Street could not be immediately reached for comment.

The Government has pointed to its white paper on Brexit strategy and the Article 50 bill which passed through Parliament, after campaigner Gina Miller won a court battle to force Ms May to hold a vote.

As the UK’s negotiating team – comprising of around 100 civil servants – works to secure a deal, Cabinet Secretary Jeremy Heywood has also been tasked with creating two new departments on exiting the EU and international trade.