The EU’s trade boss has warned the UK that a full Brexit trade deal by the end of the year is “just not possible”.

Phil Hogan, Ireland’s EU commissioner, said he was “certainly” not going to be able to meet Boris Johnson’s ambition of having a comprehensive agreement in place by 31 December.

He was echoing comments by chief negotiator Michel Barnier, who said publicly earlier this month that Mr Johnson’s timetable did not give enough time for a deal.

“Certainly by the end of the year we are not going to get everything that’s in the 36-page document on the future relationship agreed because Prime Minister Johnson decided we are going to have everything concluded by the end of the year,” Mr Hogan said at an event in Washington.

“It’s just not possible. Especially if we have to make a decision about the transition by 1 July.”

The commissioner also warned the British government that a trade deal with the US “won’t be as easy as the United Kingdom thinks”.

“We need to wake up to this reality that gamesmanship and brinkmanship are not going to work on this occasion,” he said, referring to the UK’s longstanding strategy in Brexit talks.

“If you want to do a deal together I wish you well, but I’m hearing messages from the various players in this town that it won’t be as easy as the UK and the US think; certainly it won’t be as easy as the UK thinks for the UK to strike a deal that actually meets the objectives of the administration here.”

Some UK cabinet ministers are reported to want simultaneous discussions with both Washington and Brussels on trade to play both sides off against each other. The UK has also long tried to divide the EU countries to get one-up in talks, so far without any success.

Mr Hogan, a longstanding critic of Brexiteers, added that the EU was “certainly open to suggestions” on how to manage the situation but that Mr Johnson’s decision to set deadline was not the “wisest thing”.

Bizarre: Boris Johnson drives 'Brexit' digger through boxes Show all 8 1 /8 Bizarre: Boris Johnson drives 'Brexit' digger through boxes Bizarre: Boris Johnson drives 'Brexit' digger through boxes Conservative party leader Boris Johnson drives a JCB through a fake wall POOL/AFP via Getty Images Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson during a visit to JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Prime Minister Boris Johnson sits in a cab of a JCB during a visit to its cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Britain, December 10, 2019. Ben Stansall/AFP/Pool via REUTERS POOL REUTERS Bizarre: Boris Johnson drives 'Brexit' digger through boxes A sign made for a visit by Prime Minister Boris Johnson to the JCB cab manufacturing centre in Uttoxeter, while on the General Election campaign trail. PA Photo. Picture date: Tuesday December 10, 2019. See PA story POLITICS Election. Photo credit should read: Stefan Rousseau/PA Wire Stefan Rousseau PA Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson drives a Union flag-themed JCB, with the words "Get Brexit Done" inside the digger bucket, through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty Bizarre: Boris Johnson drives 'Brexit' digger through boxes Britain's Prime Minister and Conservative party leader Boris Johnson reacts as he sits in the cab of a drives a Union flag-themed JCB, after driving through a fake wall emblazoned with the word "GRIDLOCK", during a general election campaign event at JCB construction company in Uttoxeter, Staffordshire, on December 10, 2019. - Britain will go to the polls on December 12, 2019 to vote in a pre-Christmas general election. (Photo by Ben STANSALL / POOL / AFP) (Photo by BEN STANSALL/POOL/AFP via Getty Images) BEN STANSALL AFP via Getty

The prime minister has ruled out extending the transition period beyond the end of the year and staked his political credibility on “getting Brexit done” – despite negotiating an option for extension in the withdrawal agreement he struck with Brussels.