The UK government is being taken to court over its continuing multi-million pound program of selling arms to Israel after claims they could have been used in Gaza. Unless it stops, its issuing of licenses to arms manufacturers will be legally challenged.

The lawsuit comes from the UK-based Campaign Against Arms Trade (CAAT), which is represented by law firm Leigh Day. The firm wrote to the UK’s business secretary, Vince Cable, stating that the government was acting unlawfully and that a judicial review of its activities would be carried out if it refuses to stop the exports, the Guardian reports.

"If arms from the UK are being used to commit crimes against humanitarian law, and human rights law, then export licences for these materials must be revoked immediately," Rosa Curling, of the human rights team at Leigh Day, said in a letter obtained by the newspaper.

"If this is not done, the government's current policy is unlawful and susceptible to legal challenge. We have asked the government to clarify the review of the arms export licences and requested details of all current licences to understand what is being sent so we can get a better picture of whether any of the arms supplied by the UK have been or may be used in criminal acts."

CAAT recently outlined the issue on its website, saying: “Israeli equipment used in Gaza in the 2008-9 conflict “almost certainly” contained UK-supplied components. Yet the UK has approved over £47 million in weapons sales to Israel since then – and spends millions on buying its "battle-tested" weapons exports. The UK government is supplying Israel, It has been supporting it and providing it with succour. It cannot deny responsibility for the acts it is carrying out.”

Still no arms embargo. Join the call for the UK government to #StopArmingIsraelhttp://t.co/wOxLHLrdKBpic.twitter.com/bDZPspudK6 — CAAT (@wwwcaatorguk) August 15, 2014

On Wednesday, the British government promised that it would suspend 12 licenses for its companies to sells arms to Israel if the current ceasefire were broken, just as Foreign Secretary Philip Hammond “welcomed the [five-day] agreement by all parties to extend the humanitarian ceasefire and to work towards a lasting ceasefire in Gaza, with Egyptian mediation.”

READ MORE: UK govt to block arms exports to Israel if Gaza fighting resumes

Leigh Day, however, maintained that complications arise with such promises, owing to a lack of clarity in establishing what a “broken” ceasefire means.

The lobbying group also complained that while Hammond criticised Russia for its alleged role in supplying eastern Ukrainian separatists, he failed to apply the same logic to the UK’s weapons shipments to Israel.

On August 12, the group condemned what it called “the UK government’s outrageously weak response to its own review of licensed exports to Israel,” which was overseen by Cable.

CAAT spokesperson Andrew Smith wrote in a recent press release: “We always hear about the strength of the UK's arms control policy, but this underlines how poor it actually is. Even by Vince Cable's own admission, UK weapons may have been used in Gaza. The UK's failure to even suspend these licences unless the violence resumes is simply not good enough. It is a very weak position and it will be seen as a sign of political support for the Israeli government and military.”

“The public is rightfully shocked by the bombardment that has been taking place and the UK needs to take responsibility by revoking all current licences. It should announce a full embargo on all arms sales to Israel as well as an end to all military-industrial collaboration with Israel,” Smith said.

The LDN Palestine Action Group has also joined the chorus of protest and has been campaigning across London.

Death pays a visit to BIS! They issue the licences for sales of arms to Israel! #StopArmingIsraelpic.twitter.com/dBfBDAa3O6 — LDNPalestineAction (@LondonPalestine) August 15, 2014

There are specific EU criteria for the issuing of export licenses, which are legally considered on a case-by-case basis. CAAT feels that this time this procedure was ignored, and therefore, continuing exports go against the normal criteria, which include the possible effect the business has on security and regional peace.

A parliamentary coordinator with the group, Ann Feltham, wrote: "After the slaughter of recent weeks, it beggars belief that the UK government is continuing to allow the export of components which it admits could be part of equipment used by the Israeli Defence Force in Gaza… Such equipment containing UK components has been used in Israeli attacks in the past and the licences should never have been granted in the first place."

The impact on UK military equipment manufacturers would be substantial if all arms exports to Israel cease. British arms manufacturers supply Israel with a wide variety of weapons, including components used in targeting systems and drones, as well as those included in weapons supplied to Tel Aviv by the United States.