A Tory MP has "dissociated" himself from the rightwing Traditional Britain Group after it suggested Doreen Lawrence and other black people should be "requested to return to their natural homelands".

Jacob Rees-Mogg, who was guest of honour at the group's annual dinner, expressed shock at the comments, which were posted on its Facebook site when the mother of murdered teenager Stephen Lawrence was made a peer.

The site said it was a "monstrous disgrace that this Lawrence woman, who is no friend of Great Britain, and who is totally without merit, should be recognised like this or in any other way".

It added: "In fact she, along with millions of others, should be requested to return to their natural homelands. Of course the biggest disgrace is that any party calling itself 'conservative' could have been part of this."

In other comments, first reported by the LiberalConspiracy.org blog, the group praised Marine Le Pen, the leader of the far-right French Front National, describing her by-election win as "excellent".

After the comments were made public, Rees-Mogg said he had "never been a member or supporter" of the Traditional Britain Group. The MP for North-East Somerset said he had been told some of its views were extreme, but had been reassured that this was an unfounded smear.

"I addressed the annual dinner of the Traditional Britain Group in May," he said. "This was one of dozens of engagements for a variety of Conservative groups I have carried out this year. About a day before I addressed them I received a message warning me of their rightwing connections.

"I made, in the limited time available, some investigation into these and put them to the organiser of the dinner. He denied that the Traditional Britain Group held such views and told me that it was a smear. My assistant also contacted Central Office, who had no knowledge of the group which they could give me.

"I am shocked by the comments made by members of the Traditional Britain Group which I note from the Liberal Conspiracy website seem to have been made after I had addressed the dinner. I can entirely disassociate myself with the Traditional Britain Group as I have never been a member or supporter."

Sheila Gilmore, the Labour MP for Edinburgh East, said Rees-Mogg had made a serious error of judgment. "He should make clear that he does not support the deportation of black Britons, or celebrate the French far-right National Front, or regard ethnic minority MPs as foreign," she said.

The Traditional Britain Group said today it had no links with any far-right organisations and its members were "perfectly normal conservatives", adding: "We are aware that the BBC and other media outlets describe some overseas political parties which we take an interest in (and that is all) who are opposed to alien (to cite Enoch Powell) immigration into their countries as 'far-right' although it is difficult to see the context, as those parties have whole rafts of policies on all matters."

It said "Previous speakers at these dinners have included Gerard Batten [a Ukip MEP], whose wife is Asian," the group added. "If we were the 'far-right' organisation which these blogs and communist outfits like Searchlight magazine insist, would we have invited Mr and Mrs Batten to be our guests?"