Cameron offers to help US ‘destroy’ IS

David Cameron pledged to help America “destroy” self-styled Islamic State (IS) extremists in Syria as he gave his clearest signal yet that UK forces could be asked to join air strikes.

The British prime minister said he wanted Britain to “step up and do more” if he could secure the approval of parliament as he prepared to issue a stark warning to home-grown would-be jihadists that IS wanted them as “cannon fodder”.

He will use a speech today to set out what aides said would be “significant” elements of the government’s strategy to combat the threat from fundamentalist terrorism for the next five years.

The decision to invite Labour’s interim leader Harriet Harman to a National Security Council briefing on the threat last week was seen as a further step to prepare the ground for a possible parliamentary vote to extend air strikes in the autumn.

But ministers will also be forced to explain why RAF pilots were allowed to take part in bombing raids over Syria despite MPs having voted against Britain carrying out strikes.

Downing Street has confirmed that Cameron was aware of the missions flown by a small number of aircrew embedded with US and Canadian forces despite parliament only authorising attacks on IS targets in neighbouring Iraq.

Asked in an interview for US television channel NBC if he planned to join the US-led air raids in Syria, he said: “We know that we have to defeat Isil, we have to destroy this caliphate, whether it is in Iraq or in Syria. That is a key part of defeating this terrorist scourge that we face.

“I want Britain to do more. I’ll always have to take my parliament with me. We’re talking and discussing at the moment, including with the opposition parties in Britain, what more we can do.

“But be it no doubt, we’re committed to working with you to destroy the caliphate in both countries,” he told the Meet The Press programme.

In his speech, Cameron will renew his focus on “shared values” and deliver an appeal to all faiths to “support the British way of life”.

He will dismiss complaints that new duties on schools to prevent radicalisation amount to spying on Muslim pupils as “paranoia in the extreme” and part of the “ludicrous conspiracy theories” of plots against Islam.

And he will focus his message on convincing those tempted to travel to Syria not to buy into the supposed “glamour” of fighting for IS in the region.

UK security services believe at least 700 extremists have travelled to fight alongside the self-styled IS and other fundamentalist groups, with around half thought to have returned to the UK.

A growing number of British women and girls — 43 in the past year — are thought to have gone to Syria.