Britain's former Northern Ireland secretary Peter Mandelson has said the only thing Margaret Thatcher ever told him was that the Irish were “all liars” and not to be trusted.

He revealed these details of his 1999 exchange with the Baroness, explaining why he did not want to attend the former prime minister’s funeral service. Mandelson served as Tony Blair's Northern Ireland secretary between 1999 and 2001.

The former Northern Ireland secretary said he, “Didn’t feel he knew her well enough” to apply for the tickets offered to peers.

“Although I helped to organize the Labour Party’s opposition to her policies throughout the 1980s, I only ever met her once. It was the day I was appointed Northern Ireland secretary and our paths crossed,” he said.

Speaking to BBC Radio 4 he said, “She came up to me and she said, ‘I’ve got one thing to say to you, my can’t trust the Irish, they are all liars’, she said, ‘liars, and that’s what you have to remember, so just don’t forget it. With that she waltzed off and that was my only personal exposure to her.”

Lord Mandelson, one of the central architects of New Labour, criticized the scale of the funeral but accepted the Iron Lady “reframed British politics."

“I think what she was right to do was to bring home to us the reality that Britain could not afford rampant inflation, that state monopolies needed commercializing, that personal tax rates were too high and that enterprise was too unrewarding,” he said.

“She was also right to argue that deregulation can be a valuable spur to innovation and efficiency and of course she tackled what was then a very disruptive and irresponsible trade union culture."

“But the truth is also that in cutting back the state necessarily, she overlooked what the state can also do successfully,” he said.

Meanwhile, NI First Minister Peter Robinson and a number of other guests from Northern Ireland attended the funeral of Baroness Thatcher in London.

Robinson represented the Northern Ireland Assembly at the service in St Paul's Cathedral.

Also attending were Ulster Unionist leader Mike Nesbitt and Alliance Party MP Naomi Lon, Irish Education Minister Ruairí Quinn represents the Republic of Ireland's government.

The DUP's William McCrea was one of the senior members of the Commons who received Lady Thatcher's body into the crypt at Westminster on Tuesday.

The South Antrim MP said he disagreed with a number of Thatcher's policies, particularly the 1985 Anglo-Irish Agreement.

He told the BBC, "In politics there are things that people agree with and disagree with and I think Margaret Thatcher did acknowledge in her record of looking back over her life that she had regretted things about the Anglo-Irish Agreement.”

"You can't take away the fact that she was an outstanding political figure in the UK. She brought a distinction and respect internationally back to Britain, which hadn't been there for some time."

"She was a person of renown - no-one can take that away from her."

Naomi Long said Thatcher's legacy was "very much a mixed bag,"

"It is a mark of a civilized society that we should be able to mark the passing of significant figures in a dignified way," she said.

"There is a time and a place to discuss her legacy but on the day of the funeral there is a grieving family at the center of this. She was a human being with family and friends and that is something you need to be respectful of."

About 200 states, territories and international organizations have been invited to send an official representative.