UK pilots embedded with coalition allies’ forces have been conducting air strikes over Syria against the Islamic State group.
About 20 personnel, including three pilots, had been embedded with other coalition nations’ forces, including the US and Canada.
Defence Secretary, Michael Fallon, however, said that MPs’ approval would be needed before any new UK action in Syria.
Parliament approved UK bombing of militant positions in Iraq last year. However, MPs were not asked at the time to authorise strikes across the border in Syria.
Tory MP John Baron said the personnel should be withdrawn as Parliament “said no to military intervention”.
A Labour spokesman said that the party would ask the Ministry of Defence to make a statement in the Commons 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,” he said.
In 2013, the government lost a parliamentary vote after seeking backing for military action against Syrian president Bashar al-Assad to deter the use of chemical weapons.
A government spokesperson told Sky News that: “The UK is contributing to the anti-ISIL Coalition air campaign against ISIL targets in Syria through the provision of intelligence, surveillance and reconnaissance.
“The UK itself is not conducting air strikes in Syria. But we do have a long-standing 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”.
