Boris Johnson is being actively undermined by officials within his own department over Brexit negotiations, it can be revealed.

Sky News has learnt that Foreign Office officials told Ireland's Government "not to listen to whatever he had to say" ahead of Mr Johnson's visit to Dublin a few weeks ago.

Extraordinarily, officials in Whitehall were very open with their counterparts in the Irish capital to "ignore the public utterances" of Britain's chief diplomat.

Mr Johnson visited Dublin on 17 November to meet with Simon Coveney, Ireland's foreign minister and now also deputy prime minister, for Brexit discussions ahead of next month's critical European Council summit in Brussels.

The two publicly disagreed at a press conference over when Irish border issues should be settled, while Mr Johnson claimed he was unaware of Ireland's call for a transition period lasting four to five years.


Bertie Ahern criticises UK over Irish border issue

The UK Government is aiming for a shorter two-year transition period.

Ahead of the visit, Irish officials were told "not to mind a word of what he says" - implying the Foreign Secretary was not speaking on behalf of the UK Government.

It further adds to the apparent frustration from politicians in Dublin about "confusing messages" from the UK Government on Irish border issues.

Earlier this week, Liam Fox, the International Trade Secretary, was accused of displaying a worrying lack of knowledge by former Irish prime minister Bertie Ahern.

Dr Fox told Sky News no deal can be secured on the Irish border until post-Brexit trade arrangements are settled with the whole of the EU.

Ireland has insisted it is willing to veto Brexit negotiations moving onto their second phase - on a transition period and the future UK-EU trade relationship - unless there are written guarantees from the UK to avoid a hard border on the island of Ireland.

Battle over Irish border threatens EU talks

Mr Johnson, despite spearheading the Leave campaign, has not publicly played a big role in EU divorce negotiations to date.

The revelation that Foreign Office officials are willing to be so dismissive of their boss to foreign governments will be a further blow to the Foreign Secretary.

Mr Johnson has committed a number of high-profile gaffes in recent months, while there are suggestions many within his department are unhappy with his performance since he was appointed last year.

In recent months, the Foreign Secretary has been accused of reciting an "inappropriate" poem in Myanmar and making a crass comment about those who have died in Libya.

He has also been forced to apologise for his "mistake" over the case of imprisoned British-Iranian mother Nazanin Zaghari-Ratcliffe.

A Foreign Office spokesperson said: "We do not recognise this version of events and the claims made in the article are not supported by any sources from the Foreign Office - either on or off-the-record."

A spokesperson for Ireland's Department of Foreign Affairs said: "We absolutely refute the contents of that report."