The 82-year-old activist bundled from the Labour Party conference for heckling Jack Straw over Iraq was welcomed back by embarrassed party leaders today and promptly accused them of hiring heavies "to stifle debate".

Walter Wolfgang, a Jewish refugee from Nazi Germany who has been a Labour member for 57 years, received a hero’s welcome from delegates on the Left of the party and a personal apology from the Prime Minister for his treatment by "over-zealous" party stewards.

His unrepentant return to conference capped a rough week for the party executive, which today suffered its fourth defeat at the hands of the rank and file – a record under Tony Blair’s leadership.

After interrupting the Foreign Secretary with a shout of "nonsense" and "that’s a lie" as Mr Straw defended the UK military presence in Iraq, Mr Wolfgang was physically evicted from the hall yesterday with a party colleague who tried to protest against his removal.

He was later detained briefly by police under the Terrorism Act as he tried to get back into the conference and had his accreditation pass confiscated.

Pictures of the eviction dominated today’s newspaper coverage – overshadowing an initiative on banning junk food from schools – and threatened to upstage the traditional show of unity at the end of conference.

It also gave the party an unwelcome PR headache as Scottish voters went to the polls in Livingston, the seat left vacant by the sudden death of Robin Cook, the former foreign secretary who resigned over the invasion of Iraq. In a round of television and radio interviews this morning, the Prime Minister apologised fully for Mr Wolfgang’s treatment.

"I apologise completely, totally, it shouldn’t have happened at all," Mr Blair said. "The conference is stewarded by these volunteers, and they are people who try to do a very good job. This time they were a little bit over-zealous so I fully apologise to him."

After being escorted through the conference security cordon by party officials into a large media scrum outside the Brighton Centre, Mr Wolfgang declared: "The trouble is that most stewards from the Labour Party are volunteers out of the goodness of their heart; they really are the cream of the Labour Party. But there have been people who have been irresponsible enough to hire heavies. You cannot stifle debate by hiring heavies.

"A party has to be open, it has to be open to the world and it also has to discuss international issues rather than ignoring them. If you ignore international issues they will not go away."

It was not clear to which "heavies" Mr Wolfgang was referring. Labour officials said that all the stewards inside the building were party volunteers paid at minimal rates for their work, although Brighton Centre security staff are also on duty and one may have got involved yesterday.

The stewards involved in yesterday’s eviction, rumoured to include one former Labour councillor from South Shields and a nightclub bouncer, were given the day off today.

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