British pilots took part in anti-Isis bombing campaign in Syria

British pilots have carried out air strikes in Syria, marking a significant expansion of the UK’s role in the campaign against Islamic State.

The UK pilots were embedded with coalition forces, including the US and Canada, and the number involved is understood to have been in single figures.

Details of British personnel’s involvement in strikes by allied nations’ forces were revealed by a freedom of information request from the pressure group Reprieve.

The House of Commons voted against military action in Syria in 2013 and parliamentary authorisation has so far only been given to UK air strikes against Isis in neighbouring Iraq.

But David Cameron and the defence secretary, Michael Fallon, made clear they were considering extending the military air campaign to Syria in the wake of the Tunisian beach massacre on 26 June, which claimed 30 British victims among the 38 dead.

They have indicated that they would seek MPs’ approval for an extension of air strikes into Syria, but no vote is expected before the autumn.

The revelation is likely to infuriate MPs who voted against the military intervention. John Baron, the Tory MP for Basildon and Billericay and a member of the foreign affairs select committee, called for the immediate end to UK military strikes in Syria and urged Fallon to explain himself to parliament.

“What this does show is at the very minimum an insensitivity to parliament’s will,” he told BBC Radio 4’s Today programme.

“Let’s be absolutely clear about this. We voted in 2013, when parliament had been recalled from recess, that there should be no British military intervention in Syria. We were told that No 10 had got the message and that any future intervention would be subject to a vote.

“Here we are learning that we have British military personnel engaged in air strikes, so I hope the government takes the earliest opportunity to come to parliament and explain its position because I think a number of colleagues will ask questions.”

This month Fallon said there was an “illogicality” about targeting Isis assets in Iraq but not in Syria. Downing Street has said more “thought and deliberation” are needed before putting the issue to a vote in the Commons.

The US and UK have been embedding personnel in each other’s forces since the 1950s. The frequency has grown in recent years as Nato has encouraged increased “interoperability” – making command structures, communications, equipment and other areas as compatible as possible. Forces from various nations serve on one another’s ships, planes and tanks and embedded with allied infantry.

Since the US-led coalition against Isis began a year ago, the UK has had about 1,000 personnel engaged, the bulk of them in air strikes against Iraq from the British base in Cyprus, and the rest trainers and advisers in Baghdad and Kurdish northern Iraq.

About 20 UK personnel have been embedded with US and Canadian forces, who, unlike the UK, conduct strikes against Syria. Of those, three British navy pilots, thought to have been embedded with the US, have been engaged in strikes against targets in Syria in recent months.

The Ministry of Defence said any personnel embedded in foreign nations’ forces were effectively operating as troops of that country.

It said in a statement: “The UK is contributing to the anti-Isil [Isis] coalition air campaign against Isil targets in Syria through the provision of intelligence, surveillance and reconnaissance.

“Isil poses a direct threat to the UK and to countries around the world. The UK is not conducting air strikes in Syria. But we have a longstanding embed programme with allies, where small numbers of UK personnel act under the command of host nations.

“That has been the case in Syria, although there are currently no pilots operating in this region. When embedded, UK personnel are effectively operating as foreign troops.”

Jennifer Gibson, of Reprieve, said the discovery made the current debate over UK involvement in air strikes in Syria “somewhat obsolete”. She said: “It is alarming that parliament and the public have been kept in the dark about this for so long.

“Yet more worrying is the fact that the UK seems to have turned over its personnel to the US wholesale, without the slightest idea as to what they are actually doing, and whether it is legal.

“We need an open and honest debate about UK involvement in Iraq and Syria. We can’t have that, though, until the UK comes clean about what actions its personnel are already undertaking.”

A Labour spokesperson said ministers needed to be clear about the extent of the UK’s involvement in any military action in Syria. They said Labour would be asking the MoD to make a statement on the subject to MPs in parliament on Monday.

“The programme to embed personnel with allies is extremely valuable to the development of our armed forces but the government needs to be transparent about the role they play,” the spokesperson said.

One of Labour’s leadership hopefuls, Andy Burnham, said he would not rule out giving his backing to British airstrikes in Syria in future, but that it was important that “the will of parliament must override and be upheld at all times”.

Speaking on Sky News, Burnham said the government needed to “proceed cautiously and responsibly”. He said it should learn the lessons of the past where Britain staged military intervention “without perhaps the right evidence and the right justification”.

Tim Farron, the new leader of the Liberal Democrats, said the UK air strikes in Syria would “play into the hands” of Islamist militants waging jihad in the wartorn country and neighbouring Iraq.

He told Sky News on Friday morning: “My sense is that here, in the Isis-occupied territories of Syria and Iraq, for the UK and the US to be seen to be directly involved – particularly in Syria – just plays into the hands of the Islamic fundamentalists who abuse Islam and indeed murder so many Muslims and so many other people in and around their territories. Let’s not play into their hands.”

Farron, who replaced Nick Clegg as Lib Dem leader on Thursday, added that British military strikes in Syria were “done with our name therefore should be done with our approval” and that western countries should be much more cautious about launching military interventions after Tony Blair’s “outrageous” war in Iraq.