Mrs Roche continued with her surgery after the incident

Barbara Roche, 49, the MP for Hornsey and Wood Green in north London, tackled the man at 1745 BST on Friday.

He was talking to her about his housing concerns when he produced lighter fluid and said he was going to set himself alight.

Mrs Roche wrestled with the man whilst shouting for a colleague to call the police.

After being disarmed, the man then calmed down and stayed talking to the former home office minister who stepped down in the June 2003 government reshuffle.

Lighter found

The police arrived shortly afterwards and the man, who is in his 40s and from Hornsey, has been detained in hospital under the Mental Health Act.

A police spokesman said that officers also found a lighter on the man.

"Whilst taking nothing away from the actions of Mrs Roche, we would always advise the public not to tackle persons themselves, but to call the police," the spokesman said.

Mrs Roche praised the police and other emergency services for their swift response and the professional manner with which they dealt with the incident.

Councillor killed

In January 2000, local councillor Andrew Pennington was killed during a Samurai sword attack on Liberal Democrat MP for Cheltenham, Nigel Jones.

Mr Pennington was stabbed six times and Mr Jones suffered serious injuries to his hands as he tried to fend off Robert Ashman in his surgery.

Ashman, 52, admitted the manslaughter of Mr Pennington on the grounds of diminished responsibility but a jury found him guilty of the attempted murder of Mr Jones.

He was detained in a medium secure hospital for an indefinite period earlier this month.