Theresa May greets Donald Tusk with a kiss outside Number 10 yesterday

Hungary last night broke ranks to warn that the EU faces economic devastation if it fails to achieve a post-Brexit trade deal with Britain.

Its foreign minister Peter Szijjarto demanded Brussels stop trying to punish the British people for voting to leave.

In a stinging rebuke days before the European Council summit, Mr Szijjarto said the EU had put its citizens’ security at risk by threatening to kick Britain out of projects such as the European Arrest Warrant and DNA database for criminals.

He told the Daily Mail that EU negotiators should understand the economic damage they will cause if they fail to sign a comprehensive UK trade deal.

Mr Szijjarto said: ‘If the EU is not able to come to an agreement with the UK then it will end up with a further decrease in its competitiveness, which has already suffered in recent years.

‘That is obvious if you look at the US, China, India, and other emerging countries.

‘If we are not able to come to a deal with a country that represents 14 per cent – or one seventh – of our economy, that would lead to a situation that would be very devastating for the EU.’

His comments mark a departure from the first phase of Brexit negotiations, when the 27 countries that will remain EU members after the UK has left maintained a remarkably united front.

Meanwhile Theresa May’s talks with European Council president Donald Tusk got off to an awkward start last night with a tense- looking kiss outside Number 10.

President of the European Council Mr Tusk speaks with the Prime Minister at Downing Street

Mr Tusk then claimed Brexit would be ‘much more difficult than the game against Panama’, in a jibe referring to England’s 6-1 World Cup win on Sunday.

Mr Szijjarto yesterday criticised Brussels’ attempts to exclude the UK from joint security projects.

He said: ‘I am especially against all kinds of steps to punish the British that would cause harm to the EU in the process. There are common projects like [the] Galileo [satellite system].

‘Regardless of Britain leaving the EU, they are projects that must be maintained as cooperation between the 28, because if we let you out or kick you out from this kind of cooperation it would harm the European interests.’

Pushed on why EU negotiators were taking such a hardline position if it was damaging for Europe, Mr Szijjarto said: ‘There are still many people in Brussels – without mentioning names – who look at the Brexit decision as a personal insult against them, because they simply did not believe that the British would dare make the decision to leave the EU.’

He added that the Brexit vote was caused by Brussels’ unwillingness to listen to British concerns.

‘I think if the European Commission had behaved before the referendum in a more understanding way, willing to understand more how the British mindset operates, we could have reached another type of outcome,’ he said.

Mr Tusk yesterday held talks with Mrs May on Brexit ahead of the summit of EU leaders this week.

He said he was ‘very, very moved’ by the pro-EU march in London at the weekend, when tens of thousands of protesters called for a second referendum.