The defence secretary is to say that MPs should consider allowing Britain to bomb Islamic State targets in Syria.
The RAF has been carrying out strikes in Iraq since September but Michael Fallon will say Parliament should look at the case for missions in Syria too reports BBC.
The UK does not need the backing of MPs to launch raids but Mr Fallon has said the Commons will have the final say.
He will suggest terrorist attacks, such as Friday’s tourist murders in Tunisia, may have been planned by IS in Syria.
Twenty-nine of the 38 tourists killed on the beach in Sousse on 26 June have been confirmed as British. Student Seifeddine Rezgui, 23, said to have had links to IS, was shot dead by police after carrying out the attack.
Prime Minister David Cameron later said IS posed “an existential threat” to the West, and its members in Iraq and Syria were plotting “terrible attacks” on British soil.
Mr Cameron was defeated in the Commons in 2013 when Tory rebels joined forces with Labour to oppose air strikes on Syrian government targets designed to deter the use of chemical weapons.
The 2013 vote focused on the Syrian President Bashar al-Assad, not IS militants.
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.