Several inquiries are under way at Port Talbot

Speaking at Cardiff Crown Court on Monday, the judge said that in relation to the Llanwern incident, there had been "very grave breaches" of the Health and Safety at Work Act.

The hearing was told that the management failed to react to warnings of water under equipment where the blast happened in September.

Six Corus employees working at Port Talbot remain critically ill on life-support machines at Swansea's Morriston Hospital after a series of explosions at furnace number five last Thursday.

Two opposition AMs have claimed safety fears about the plant were raised with the first minister last year.

Plaid Cymru AM Janet Davies said she put the issue of safety at Port Talbot to Mr Morgan in March last year.

Tory AM Alun Cairns - whose father works at the plant - has claimed that there were widespread concerns among workers about the condition of the lining of furnace number five.

Stephen Galsworthy died in the explosion

"There are claims the fifth blast furnace has a poor operating record, with reports of several breakouts in the last five years," said Mr Cairns.

"Staff were concerned when only two weeks ago it was announced that the furnace wouldn't be re-lined for at least another two years."

But the company said the furnace was in good repair, routinely maintained and was not due to be re-lined until 2005.

Mrs Davies AM said she had become concerned by rumours of a lack of maintenance at the plant.

"There was a very, very real concern voiced to me about the condition of the number five blast furnace," she said.

"The first minister said he had also heard these concerns from workers at the plant.

"I challenge Mr Morgan to tell us all what action he took following this discussion."

An assembly spokesperson has confirmed Mr Morgan met Corus representatives in April following Mrs Davies's requests.

The company assured him maintenance was in hand.

Mrs Davies has now called on Corus - which must decide whether or not to rebuild the wrecked number five blast furnace - to commit itself to steel production in Port Talbot, safeguarding jobs in the area.

Andrew Hutin: Body found by rescuers

Aberavon MP Hywel Francis said the inquiries into the explosion would separate the facts from the rumours.

"We have given our fullest support to ensure we get to the answers we need," he said.

A minute's silence has been planned at the church for Thursday at 1717GMT - exactly a week after the blast - as the town continues to mourn.

Stephen Galsworthy, 25, and Andrew Hutin, 20, died in the blast, which caused an escape of molten metal on Thursday.

Corus, South Wales Police and the Health and Safety Executive have all launched investigations into the incident.