British diplomat who wrote article 50 says 'people should be allowed to vote on final terms of Brexit'

'It might be not a bad idea to ask the country in a general election, or possibly another referendum, whether this is actually what it had in mind'

Theresa May gives her speech at Conservative conference (Reuters)

A British diplomat who penned article 50 has urged Theresa May to let the British public vote on the final terms of Brexit.

Lord Kerr of Kinlochard, a crossbench member of the House of Lords and a representative to the European Union who drafted the formal mechanism for leaving the bloc in 2003, suggested a general election or referendum should be held on whether Brexit negotiations have lived up to the promises made during the Referendum.

Lord Kerr, who confessed he did not think article 50 would ever be enacted when he drafted it, told The Guardian: “Once the government, some way down this process, has established clearly what Brexit will be like, if it turns out that Boris’s policy on cake doesn’t work, then it might be not a bad idea to ask the country in a general election, or possibly another referendum, whether this is actually what it had in mind.”

Foreign Secretary Boris Johnson, one of the most prominent leaders of the Leave campaign, said during the referendum he was “pro having my cake and pro eating it.” However, the approach has been condemned by European leaders, including the President of the European Commission Jean-Claude Juncker who insisted Britain “could not have a la carte access” to the benefits of the EU after Brexit.

Lord Kerr also claimed Ms May would allow Parliament to vote on if or when to trigger Article 50, even if the two legal cases currently going through the High Court, aiming to force the Prime Minister to get parliamentary approval before triggering Article 50, fell through, saying a vote would be "risk-free" for the Prime Minister.

His comments come after the Ms May unveiled a far tougher stance than she has previously taken on EU withdrawal in her opening speech to the Conservative conference last week, in which she signalled backing a hard Brexit and even directly attacked those who want a compromise deal to allow the UK single market access.

Lord Kerr attacked Ms May’s speech saying “it has played very badly in continental Europe”, adding that her words had “caused consternation” in Europe.

On Saturday, business leaders demanded that Ms May moves to rule out the “worst aspects” of a hard Brexit break with the EU. Confederation of British Industry (CBI) director general Carolyn Fairbairn said it was a matter of urgency because uncertainty was impacting on investment decisions.

One of the country's top universities has also warned the Government it will stand by its foreign academics following reports it had banned them from advising ministers on Brexit.

Ms May has said she will formally trigger the two-year exit negotiations by the end of March.