THE BBC has been forced to apologise for a "wholly disrespectful" blunder after the Irish tricolour was displayed at the Platinum Jubilee to represent Northern Ireland.

The green, white and orange flag appeared on a screen at the Buckingham Palace concert on Saturday when comedian Doc Brown spoke about being "proud to be British". 

And the move sparked a fierce backlash online given Ireland has not been part of the UK since 1937 and became a republic in 1949.

The montage saw Doc Brown refer to England's "three lions", the Welsh dragon, and included both the Irish tricolour and Scottish Saltire.

The Ulster Banner, the unofficial flag of Northern Ireland, is regularly flown at sporting fixtures in the country.

A BBC spokesperson said: "The incorrect flag appeared in a brief montage during Doc Brown's appearance last night.

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"We apologise for the error, and the sequence will be edited on iPlayer."

Terry Brennan, communications officer of Limerick Council, said: "@BBCOne did you just include the Irish tricolour in a song about being 'proud to be British'. Laaaddddssss!!!!”

Another Twitter user wrote: "What's that about, tricolour. Since when are we British?"

Unionist politicians in Northern Ireland also hit out at the use of the flag.

DUP MP for East Londonderry Gregory Campbell said: "The Platinum Party at the Palace was a part of what will be regarded as an outstandingly successful recognition of Her Majesty's 70 years as the Monarch.

"It was unfortunate that in a very short video clip during the event when the four Nations that make up the United Kingdom were visually represented by logos or flags that the Irish Tricolour was used instead of the Ulster Banner.

"Hopefully those responsible will have realised their mistake and will ensure that in the event of any future occasion where the four countries of the UK are to be visually represented, more care is taken to ensure a mistake like this one is not repeated."

TUV leader Jim Allister, who was elected as an MLA for North Antrim in last month's Stormont election, added: "Quite an appalling and wholly disrespectful blunder which contrasts with the professionalism of the range of Jubilee events."