UK prime minister David Cameron is under mounting pressure to abandon his latest summer holiday and recall parliament to fully explain his policy on the crisis in Iraq.

And in an unusually blunt criticism the former head of the Army, Baron Richard Dannatt, dismissed as "dangerous and glib" the prime minister's claim he would not put British "boots on the ground" in Iraq.

If the UK helped supply arms to Kurds fighting Islamic State, as planned, then British soldiers may well be deployed to Iraq to train them.

"If that is what it takes then that is what we must do. To be caught up on 'no boots on the ground' is a rather dangerous and glib thing to say," the former general said.

Confused pollicy

His words have highlighted the problem facing the prime minister, and the danger that, forces sent to Iraq in any capacity could be drawn deeper into the conflict.

And, having declared there will be no boots on the ground, deploying military personnel to train Kurdish fighters in the use of weapons, will be seen as a that will be seen as a major change of policy.

And it is that apparently loose use of language that is causing problems for the prime minister.

After days of confusing signals from ministers over the level of the UK's military involvement, Cameron attempted to clarify his policy on Monday by insisting there would be no new war in Iraq and no British "boots on the ground".

But as MPs from all sides claimed he had failed to set out a clear and coherent strategy, the prime minister left London for his third summer holiday on Tuesday morning, declaring he was always in control of policy because he had access to a BlackBerry device.

That has left many MPs angry that, only 48 hours after warning of the serious threat to the UK from Islamist militants, the prime minister has not only flatly refused to recall parliament to inform and consult MPs on government policy, but chosen to take a family holiday in Cornwall.

Labour's Ann Clwyd, a former special envoy on human rights in Iraq, said Cameron's decision to go ahead with his holiday was "ridiculous".

"I can't believe he has pushed off if he thinks Islamic State is such a threat," she said.

MPs need more than smartphones

Labour's John Mann, who has already urged a recall of parliament, added: "Government by BlackBerry is not any kind of Government. If I were prime minister, I wouldn't be taking a holiday."

And Conservative MP Bob Stewart, a former Army officer, said the prime minister's position on the possible use of military force remained unclear.

But the most pointed criticism came from Baron Dannatt, a former defence adviser to the prime minister, who not only claimed the nation would expect parliament to be recalled, but delivered that stinging criticism of the prime minister's language about boots on the ground.

Far from clarifying his position, the prime minister has succeeded only in further confusing the issue, angering MPs and leaving many questions unanswered.

And the best and most appropriate place for those questions to be answered is in the Commons chamber.