The government was last night warned that hard hitting measures to “flush out” illegal immigrants could cripple Norfolk's small businesses and make the county's legal migrant workers unemployable.

The government was last night warned that hard-hitting measures to "flush out" illegal immigrants could cripple Norfolk's small businesses and make the county's legal migrant workers unemploy-able.

Under the proposals, firms employing illegal workers and failing to carry out appropriate checks could be fined up to £10,000 per offending employee to cover their deportation costs.

The law would recommend that companies check foreign employees' credentials at least every 12 months and even employers who report a worker they suspect is illegal could face a fine of thousands of pounds.

Migrant workers' groups and small businesses in Norfolk say the legislation will load smaller companies with a costly bureau-cratic burden and discourage employers from taking on foreign workers altogether.

The Thetford-based Keystone Development Trust helps more than 2,000 migrant workers, mainly Polish and Portuguese, in Norfolk with education and employment support.

Project manager at the trust Elisa Pinto said that the new system would have to be backed up with appropriate training for employers on how to check an employee's credentials, to allow them to feel confident about taking on migrant workers.

She said: "If employers feel unsure they could decide not to take on foreign workers because they are worried about the consequences. The government needs to provide the training to know what to look for.

"Migrant workers at the moment are used to carrying ID cards but there could also be a lot of problems if the government starts asking them to send off for more papers from the Home Office."

The mid-Norfolk branch of the Federation of Small Businesses added its voice to the dissent, saying the proposals would both stifle fledgling business growth and threaten their survival.

Branch secretary Derek Wright said that small firms would not have the necessary expertise or equip-ment to spot what are often sophisticated forgeries.

"If a small business were not to spot a problem with the paperwork it could be broken by one of these fines, ruining the person and their family; it's just not the way to go," he said.

"If there is a discernible risk of a fine when taking on foreign workers then I think small businesses may say 'No way, I am not going to do it'.

"This will put the brakes on the progression of small businesses. Taking on staff is a very big step and it becomes a lot more difficult when one suddenly find oneself with the burden of policing the government's schemes for it."

But one of the largest employers of migrant workers in the county Bernard Matthews was happy with the suggestion.

A spokesman said: "Bernard Matthews has always had regular measures in place to ensure appropriate documentation is in place; it works closely with the authorities and already employs the measures outlined in the new bill."

Immigration minister Liam Byrne said the legislation would create a "hostile environment" for illegal workers.

He said: "What we are proposing here will, I think, flush illegal migrants out.

"We will insist that businesses do the right checks. It's not acceptable any more to break the rules and turn a blind eye," he said.

The legislation would not appear to place extra burden on local police or council workers as it would be enforced by a network of 1,200 "compliance officers", which will be set up by the Home Office at a cost of £10m-£20m.

A new telephone helpline for employers to get advice will also be piloted later this year. The consultation paper is open until August 7.