A cross-party committee of MPs has warned that the government's plans to regulate the arms industry may not prove fully effective.

The Commons committee on strategic export controls - which is comprised of the defence, foreign affairs, international development and trade and industry committees - said that current proposals to toughen British law were an "inadequate halfway house solution".

Proposals for secondary legislation under the Export Control Act would cover the regulation of British citizens abroad if they were trading in long-range missiles and torture equipment, or trading with an embargoed destination.

But the MPs warned that "there is a distinction between trade in torture equipment and trade in, for example, small arms, which will only sometimes be reprehensible".

"But the reprehensible trade in small arms is as damaging to the lives of millions of people around the world as trade in the types of equipment to which the government intends to apply extraterritoriality - if not even more damaging.

"We conclude that it would be a missed opportunity if the government failed to regulate all UK citizens and companies who are involved in trafficking and brokering activities abroad which, if conducted in the UK, would not be granted a licence."

The regulations set out by the government would only cover an "incomplete set of limited circumstances", the committee said.

"The arm of the law should reach out to British subjects based overseas who are involved in all those aspects of the arms trade which any civilised nation would regard as reprehensible - including the proliferation of small arms.

"We acknowledge that there are real practical problems in attempting to extend national jurisdiction over actions carried out abroad. In our view they are worth attempting to solve.

"But it makes no sense to try to solve these problems, as the government proposes, for oversized handcuffs, but not for small arms."

Foreign Office minister Mike O'Brien indicated that the government was aiming to make the arms control regulations "even more modern and effective".

"This government has made unprecedented improvements to the transparency and accountability of UK arms export control. However we are not resting on our laurels, and we continue to work towards further improvements," he said.

O'Brien added that while many of the issues set out in the report were "complex", ministers would respond to them as soon as possible.

Shadow defence minister Gerald Howarth backed a warning from the MPs that the plans could also prove bureaucratic.

"The truth is that no evidence has been produced to suggest that the existing raft of controls is being breached, thereby warranting the vast and costly additional burdens now being proposed," said the study.

"The government must rethink this policy now before it inflicts serious and unwarranted damage on a vital - and highly successful - sector of British industry."