A full Commons debate could be held on the developing crisis in the Middle East but not in Government time, a senior Cabinet minister has said.

Commons Leader Andrew Lansley said he would discuss whether time could be found with the backbench business committee, blaming legislative pressures for not scheduling such a debate in Government time.

Tory MP Tobias Ellwood warned the conflict in Iraq as it spilled over from Syria represented a more significant global event than clashes in eastern Europe between Ukraine and Russia.

The Bournemouth East MP said it was unknown when the Government might seek Parliament's support "in designing any response" as he called for an urgent debate.

Mr Lansley said: " You will appreciate the Foreign Secretary took immediate steps to update the House on Monday.

"So far as the debate is concerned... I can't promise an immediate debate, we have legislative pressure on Government time.

"I will have this conversation with the backbench business committee. In this Parliament we have given time to the backbench business committee to bring forward issues of importance to members across the House.

"I have seen and heard from MPs that they do feel the need for a debate relating to issues in Syria and Iraq."

A Government-sponsored debate would be seen as a bigger step, with a motion in the name of the Prime Minister or other senior ministers.

Backbench motions have no force or effect beyond demonstrating the will of Parliament. They are often drafted on a consensual basis in a bid to avoid the need for a vote of MPs.

Shadow Commons leader Angela Eagle had earlier questioned whether a further statement on British fighters in the conflict should be organised.

She said: "Iraq remains under violent siege from Islamic militants who seem set on overthrowing the Government, terrorising the population and dividing the country.

"The humanitarian situation is continuing to deteriorate and hundreds of thousands have been forced to flee their homes.

"Given the Prime Minister said yesterday there could be as many as 400 British citizens fighting for Isis, will you arrange for an oral statement on how the Government will coordinate across departments to ensure those fighters don't pose a risk to citizens if they return to the UK?"

Mr Lansley replied: "You will be aware of the statement the Foreign Secretary made on Monday and he had the opportunity further to respond to questions on Tuesday.

"I think I can make clear and the House will agree we regard developments in relation to Iraq as extremely serious, the fighting continues in Baquba and close to Baghdad as well as in the north of the country.

"Isis as a group are a violent and brutal group, we have to make sure we understand what is happening and the way it is appropriate for us to respond."