The government must shut the cockle beds in Morecambe Bay where 19 Chinese workers died, the local MP has said.
Bereaved relatives want answers about the deaths
Labour's Geraldine Smith told the Home Office and fisheries ministers there must be a full safety investigation.
The MP, who warned the Home Office last year about the risks to migrant cocklers in Lancashire, wants a Health and Safety Executive review.
The Commons Environment Committee later said it would reopen its inquiry into "gangmasters" running migrant workers.
In a report published five months ago, the committee
accused the government of failing to confront the problems in the industry, describing the enforcement of existing legislation as "unco-ordinated".
It will now ask ministers to appear before it again to see if further action is needed.
And Britain's main construction union is launching a campaign to expose gangmasters who are exploiting cheap migrant workers.
Ucatt says problems exposed in the cockle industry and agriculture, are also rife on building sites up and down the country.
The moves came hours after a group of up to 40 cocklers narrowly avoided disaster after becoming stranded only yards from the site of last week's tragedy.
A lifeboat was scrambled when the group was spotted in difficulty in an area known as Priest Skears.
The group, all believed to be English, managed to make their way back to shore, according to police.
The alert came shortly after a memorial service was held for the 19 cocklers who drowned in the bay.
Ms Smith says she now thinks the government is "moving in the right direction" over the regulation of gangmasters.
"I think before this appalling tragedy the government were looking at a voluntary licensing scheme. I don't think that will work. You need mandatory enforcement," she said.
A Buddhist prayer service, held by 15 local monks, also took place on Thursday for the 19 who drowned.
Police are still investigating the tragedy after bailing all seven people arrested on suspicion of manslaughter.
Cocklers have now returned to Morecambe Bay
Ms Smith wrote to the Home Office on 28 June 2003 to describe the plight of migrant workers, and urge the Immigration Service to intervene.
The MP said: "Unable to speak English and under the control of a gang master, these people were being paid one-fifth of the standard rate for their work.
"They were also being transported 20 to a boat in waters renowned for their currents and quicksands, where an experienced local fisherman would not consider carrying more than six."
'Threatened and intimidated'
But Home Office Minister Fiona Mactaggart replied, saying "resource issues" meant there was little point in the Immigration Service intervening.
The Home Office later said in a statement that the correspondence had referred to one specific incident, and was "not indicative" of a general lack of co-operation.
Home Office Minister Hazel Blears told BBC Radio 4's Today programme: "I do not accept that things have been missed after warnings given.
"There was a police operation involving the Department of Work and Pensions last year and an immigration operation in August last year as well.
"But this community is difficult to protect sometimes. There are forces with the community that mean people are threatened and intimidated."