Paul Murphy was carried out by paramedics on a stretcher

Mr Murphy collapsed in the Conference Hall in Brighton on Tuesday afternoon, shortly before he was due to address delegates, and was taken out of the conference hall on a stretcher.

Within an hour of the incident, Mr Murphy's ministerial colleague Angela Smith told the BBC that he was now "fine".

She said it appeared the 55-year-old may have been overcome by the heat shortly after Tony Blair had finished his keynote address to delegates.

A Northern Ireland office spokesman later confirmed he had been discharged from the Royal Sussex Hospital in Brighton and would spend the next few days recuperating.

Details of Mr Murphy's speech

He also said tests at the hospital had showed Mr Murphy was not seriously ill.

The speech that Mr Murphy was due to deliver has not been rescheduled but instead its text was released to delegates and journalists covering the conference in Brighton.

A Northern Ireland Office spokesman said: "Mr Murphy felt unwell as he was sitting in the hall just after the prime minister's speech and fainted.

"At no time was he unconscious and there's no question of it being a heart attack.

Mr Murphy is a former Welsh Secretary, and has been MP for Torfaen since 1987.