Organisers of the arms fair at the ExCeL exhibition centre ejected two companies after an MP revealed they were promoting illegal weapons.

French firm MagForce International and Chinese company Tianjin MyWay International Trading and their staff were ejected from the Defence and Security Equipment International arms fair in Custom House after Green Party MP Caroline Lucas raised concerns in the House of Commons.

She said the companies were promoting handheld projectile electric shock weapons, weighted leg cuffs and stun batons.

The firms have broken British law by displaying them in marketing literature at the fair, a DSEI spokesman confirmed.

Ms Lucas said people could have no confidence in Britain’s policy on selling illegal weapons and that DSEI’s organisers have shown “time and time again” they cannot guarantee exhibitors remain within the law.

She said: “I am very pleased that they have been ejected but I think it is enormously worrying that it takes a question in Parliament to make DSEI do their jobs properly.

“One can have no confidence that the policy on selling illegal weapons is being upheld properly at all.”

The DSEI spokesman said the firms had their stands shut down and staff ejected as soon as the fair’s compliance team became aware they had breached regulations.

The spokesman said: “No items can be bought and sold at DSEI. However, in displaying this marketing literature, Tianjin MyWay International Trading Co. and Magforce International have broken British law. Enforcing the law at DSEI is the responsibility of HMRC, who have teams on site throughout the show for this purpose.

“The HMRC is supported in its duties by the Export Control Organisation and an internal DSEI compliance team. Once the DSEI compliance team became aware that Tianjin MyWay International Trading Co. and MagForce International had breached the compliance regulations their stands were immediately shut down and their staff ejected from DSEI.”

The bi-ennial arms fair attracts opposition from anti-war campaigners who believe it fuels the wars of tomorrow and plays a huge part in arming repressive regimes.

A spokeswoman for Campaign Against Arms Trade said: “The really shocking thing about DSEi is not that arms companies sell “banned” or “illegal” equipment; it is that almost everything on display, however dangerous and destructive is “legal”.

“As far as CAAT is concerned every company is a rogue company and the arms fair should not be held at all.”

Thousands of international visitors, including military personnel and those responsible for buying defence equipment, attend the event.