First Minister Alex Salmond yesterday gave his support for the "fullest possible" inquiry into the circumstances of Scotland's worst industrial accident in a generation.

He also pledged to meet the families of the victims of the Stockline factory blast, in which nine people were killed and 33 injured.

The owners and operators of the Glasgow factory, ICL Plastics and ICL Tech, were last month fined £400,000 for breaches of health and safety procedures which led to the explosion more than three years ago.

The families branded the sentence an insult and called for a public inquiry.

Elish Angiolini, the Lord Advocate, met family representatives earlier this week and has promised to make an announcement on an inquiry by the end of this month.

In the Scottish Parliament yesterday, Patricia Ferguson, the Labour MSP for Glasgow Maryhill, pointed out that because the companies had both pled guilty in court, many of the circumstances surrounding the explosion had not been aired in public.

"Would the First Minister agree, therefore, that a full judicial public inquiry is necessary in order that all the lessons of this tragedy can be learned?" she said.

"The most appropriate way to proceed is with an inquiry initiated by the UK Government and the Crown Office working in tandem so that we can ensure that we send out a signal that in this country it is completely unacceptable that nine people should lose their lives just because they went to work."

Mr Salmond said there could be three types of inquiry into the tragedy; one ordered by UK ministers under the Health and Safety at Work Act, one ordered jointly by Scottish and UK ministers, or a fatal accident inquiry.

The First Minister said MSPs should leave the final decision on what type of inquiry is to be held to the Lord Advocate.

He said: "I have offered to meet the families and their representatives, but I think the whole chamber would join with me in welcoming the fact that the Lord Advocate has undertaken to move this process forward and make a decision in such early course."

Mr Salmond added: "I think given the nature of the criminal proceedings, which was a successful prosecution, but obviously meant that some of the evidence was required to surface in the course of the proceedings, all are agreed that an inquiry in public is necessary."

A spokesman for the Crown Office said: "It is anticipated that a decision will be taken before the end of September."

Ian Tasker, the assistant secretary of the Scottish Trades Union Congress, said any inquiry must look at the type of punishment which can be imposed on companies found guilty of breaching health and safety legislation.

He said: "The fullest kind of inquiry would have to involve ministers from the Westminster Government and that would be something we would be raising with the First Minister when we meet."