Unionist lawmaker Kwok Wai-keung on Wednesday called on the authorities to impose tougher penalties on employers who violate labour import rules.

In recent months, several firms have been banned from applying for further imports for up to two years. In one case, a restaurant received the executive sanction after it was found to have sacked local workers after bringing in outsiders.

Kwok, from the Federation of Trade Unions, said such sanctions might not have much of a deterrent effect, noting that non-locals already brought in by firms can stay on in their jobs.

"There comes the problem - imported workers often sign two-year contracts. So even though the firms were given a two-year ban, they've already imported enough people," he told RTHK's In the Chamber programme.

"The firms often make personnel changes after two years, and the ban would then be lifted... It's almost as though such executive sanctions were tailor-made."

The lawmaker called on officials to consider stiffer penalties as soon as possible.

"We hope the penalties would be effective. For example, for firms that hired through unreasonable means, does it amount to making false declarations? Or could there be fines or other criminal liabilities?" he said.

Kwok also said to protect the jobs of locals, the government should impose more limitations on labour imports, such as restricting the import ratios for each corporation as well as each job type.