Isis threat: Cameron wants an alliance with Iran

PM calls on Tehran to engage with the international community to beat extremists

David Cameron has said the Islamic State poses a threat to Britain's safety (Getty Images)

Britain must prepared to ally itself with Iran to combat the “shared threat” of Sunni Islamist extremists in Iraq and Syria who want to create “a terrorist state” that could extend to “the shores of the Mediterranean,” David Cameron has said.

Suggesting that it was now in the UK’s national interest to put aside decades of enmity with the Shia regime in Tehran, the PM called on Iranian President Hassan Rouhani to “engage with the international community” in combating Isis.

Mr Cameron even hinted UK opposition to the regime of President Assad in Syria could be tempered by the threat from Isis. He warned Islamic fighters had the “ancient city of Aleppo firmly within its sights”, where Syrian Government forces are fighting.

The new position reflects a growing realisation that US and British opposition to Assad and support for Sunni rebels in Syria have allowed Isis to grow in power and create what Mr Cameron described as a “so-called caliphate” across large swathes of Syria and Northern Iraq. But it will cause deep anger in Israel that still believed the Iranian regime is intent upon its destruction and is misleading the West promises of a deal on its nuclear programme.

In an article for the Sunday Telegraph, Mr Cameron wrote that Britain was in the midst of a “generational struggle” that would last “for the rest of my political lifetime”.

“Already IS [Isis] controls not just thousands of minds, but thousands of square miles of territory... It makes no secret of its expansionist aims... And it boasts of its designs on Jordan and Lebanon, and right up to the Turkish border. If it succeeds, we would be facing a terrorist state on the shores of the Mediterranean and bordering a Nato member. This is a clear danger to Europe.”

He continued to rule out a greater role for UK troops in Iraq, saying that the effort must be put into strengthening Kurdish and Iraqi forces.

Mr Cameron’s policy faced criticism from the Church of England, which accused the Government of appearing to have no “coherent or comprehensive approach” to tackling Islamic extremism.

In a strongly worded attack – backed by the Archbishop of Canterbury – the Bishop of Leeds said “many” top clergy were seriously concerned.

The Rt Rev Nicholas Baines has written to the PM, questioning whether there is any long-term strategy and criticising a “growing silence” over the fate of the plight of persecuted Christians.

Writing inThe Independent on Sunday, General Sir Richard Shirreff, former Deputy Supreme Allied Commander Europe, said: “This unhappy saga highlights all too graphically the collective loss of nerve in matters of defence and security, increasingly the defining characteristic of this government.

“The consequence has been knee-jerk reactions dictated by events, whether last year's abortive attempt to launch Tomahawk missiles at Syria, or last week's response to events in northern Iraq.”