Michel Barnier has thrown his weight behind a chorus of EU leaders who warn post-Brexit trade talks will tank if Boris Johnson refuses to obey Brussels red lines.

The bloc's chief negotiator insisted a common rule book of standards, state aid and tax would be a deal-breaker in any agreement to prevent a 'race to the bottom'.

But the Prime Minister yesterday ruled out signing up to a deal which chained Britain to alignment with the EU, setting up a crunch showdown when trade officials meet in the New Year.

And in a clear signal that he is prepared to forge fresh economic partnerships elsewhere, Mr Johnson revealed he discussed an 'ambitious trade agreement' with his Japanese counterpart Shinzo Abe.

Mr Johnson, whose withdrawal bill sailed through the Commons yesterday, is now racing to secure a trading relationship before the end of the transition period next December.

On a visit to a military base in Estonia today to dish up Christmas lunch to British troops, he swatted away interview questions over whether he was pursuing a hard Brexit, refusing to answer.

However European politicians, including the Irish premier, have made their feelings clear and poured cold water on a deal which does not safeguard common standards of good crossing the Channel.

Today, EU chief negotiator Mr Barnier echoed their concerns and said his central interest was forging a deal to safeguard common social and environmental standards.

Michel Barnier (pictured in the European Parliament on Wednesday) has throw his weight behind a chorus of EU leaders who warn they will scupper any post-Brexit trade deal if Boris Johnson refuses to obey Brussels red lines

The Prime Minister (pictured with British troops in Estonia today) yesterday ruled out any such alignment with the bloc in the terms of the agreement he hoped to strike

Looking for EU allies? Mr Johnson walks with Estonian Prime Minister Juri Ratas arrives at the Tapa military base near Tallinn, Estonia, to meet British troops during a one-day visit to the Baltic country

In a clear signal that he is prepared to forge fresh economic partnerships elsewhere, Mr Johnson revealed he discussed an 'ambitious trade agreement' with his Japanese counterpart Shinzo Abe (pictured at the G7 summit in Biarritz)

He wrote for the Project Syndicate website: 'Like the UK, we will keep our strategic interests in mind.

'We know that competing on social and environmental standards – rather than on skills, innovation, and quality – leads only to a race to the bottom that puts workers, consumers, and the planet on the losing side.

'Thus, any free-trade agreement must provide for a level playing field on standards, state aid, and tax matters.'

He is hoping to broker a comprehensive free-trade deal with the EU, but these plans are under threat of derailment by Brussels leaders.

Irish Prime Minister Leo Varadkar said Mr Johnson's pivot towards a 'harder Brexit' in the wake of his thumping election win made a deal with the bloc less likely.

It stems from fears the UK wanted to 'undercut' Europe on food, health and product safety after it exits.

He warned a 'good trade deal' for Ireland was looking increasingly unlikely after the stance taken by Number 10 since the Tories' thumping General Election win.

Mr Varadkar told journalists: 'It is going to be difficult to secure a good trade deal for Ireland, principally because Boris Johnson has fixed on a harder Brexit than we anticipated under his predecessor or at the time of the referendum, and that is one where he talks very much about divergence.

Boris Johnson arrives in Tallinn, Estonia, ahead of meeting British troops at the Tapa military base during a one-day visit to the Baltic country

Boris Johnson coming out of Scotts in Mayfair last night after his withdrawal agreement sailed through the Commons

Taoiseach Leo Varadkar warned the UK was embarked on a 'harder Brexit than anticipated'

The Tory leader (pictured serving British troops overseas in Estonia today) told MPs on Friday that the 'oven was on' when it came to delivering Brexit next year but said there would be 'no alignment' to EU rules

'The harder approach being taken by Prime Minister Johnson is a risk to us and that is evident.'

The Irish PM's concerns were mirrored by Council President Charles Michel who tweeted that 'a level playing field remains a must for any future relationship'.

It sets Downing Street on a collision course with the EU when trade officials meet to thrash out a deal in the new year.

Mr Johnson is adamant not to be shackled to the EU's rules, and told MPs on Friday that the 'oven was on' when it came to delivering Brexit but said there would be 'no alignment' to EU rules once the transition period ends in 2020.

Before those talks begin, the PM will look to switch off from Brexit over the Christmas break – an example Number 10 is rumoured to have told all ministers to follow.

Yet he did have a telephone call with Prime Minister Abe to lay the groundwork for a trading relationship.

A Downing Street spokeswoman said: 'The Prime Minister spoke to Prime Minister Abe of Japan who congratulated him on his success in the general election and expressed his condolences to the victims of the London Bridge attack.

'The leaders agreed to continue to strengthen the alliance between our countries, including on security and defence, and by working together to pursue an ambitious trade agreement that builds on the EU-Japan Economic Partnership Agreement.

'They also discussed the importance of our continued co-operation on global issues, including climate change, and looked ahead to the COP26 (United Nations Climate Change Conference) summit that the UK is hosting in Glasgow next year.'

The PM met British soldiers in Estonia today, where served serve Christmas lunch to the 850 troops from the Queen's Royal Hussars at the Tapa military base near the capital Tallinn.

Along with personnel from Estonia, France and Denmark, they lead the Nato battlegroup to protect Europe's eastern border with Russia.

Mr Johnson also held a bilateral meeting with Estonian counterpart Juri Ratas during the one-day visit.

His trip comes as Defence Secretary Ben Wallace warned serving personnel to be braced for cutbacks as part of his bid to secure more long-term investment in defence.

The PM squints as a camera flashes and is shielded from the rain by an umbrella-holding doorman

It's been a relentless few weeks for the Prime Minister, which saw him backed by voters in a general election before he turned his attention to getting Brexit done by the end of January

Speaking to BBC Radio 4's Political Thinking podcast, the Cabinet minister said: 'The best thing I can do for the men and women of the armed forces is to make sure that we cut our cloth to match our ambition, that manage expectations and say to the [service] chiefs that your appetite has to match your stomach.

'By doing so we build our credibility with the Treasury and Number 10 to say, 'Look, we have sorted out our house, when you give us some more money we will deliver on what we're trying to do and there will be no tricks'.'

He also confirmed reports that the PM's chief adviser Dominic Cummings will be involved in a major shake-up of defence procurement after the strategist wrote a number of scathing blogs about the Ministry of Defence before joining the Government.

Mr Wallace added: 'Dom is full of amazing ideas where he has spotted loads of improvement in infrastructure and technology procurement and he has spotted how that as our technology horizon changes, how we procure has to happen differently and I am incredibly supportive of what he is talking about.'