London, Dec 16 (IANS): British Prime Minister Theresa May has attacked one of her predecessors, accusing Tony Blair of "undermining" the Brexit talks by calling for another referendum.

She called his comments an "insult to the office he once held" and said MPs could not "abdicate responsibility" to deliver Brexit by holding a new poll, BBC reported on Sunday.

In London last week, Blair said MPs might back a new vote if "none of the other options work".

In response to May, he insisted that a new referendum was democratic.

"Far from being anti-democratic it would be the opposite, as indeed many senior figures in her party from past and present have been saying," he said.

On Thursday, about 10 Labour MPs met David Lidington -- who is May's de facto second-in-command -- to argue for another public vote.

Sources close to Lidington said it was "pretty standard stuff" and he was not "planning for or advocating a second referendum".

Many senior Labour figures are deeply uneasy about endorsing another referendum.

The government is also opposed to any further referendum, saying the public made a clear choice when they voted in 2016 to leave by a margin of 51.9 per cent to 48.1 per cent.

May's criticism of the former Labour prime minister was striking for its anger.

The Prime Minister said: "For Tony Blair to go to Brussels and seek to undermine our negotiations by advocating for a second referendum is an insult to the office he once held and the people he once served."

She added: "We cannot, as he would, abdicate responsibility for this decision. Parliament has a democratic duty to deliver what the British people voted for."

After postponing the vote in Parliament, May travelled to Brussels to make a special plea to European Union leaders in a bid to make her deal more acceptable to MPs.

However, the EU said there could be clarification but not renegotiation.

The Labour leadership has been under pressure to call a vote of no confidence in the government.