The West is seeing price of not getting involved in Syria, warns Osborne

Western nations are seeing "the price of not getting involved" in Syria, George Osborne warned as the Government stepped up efforts to win the support of MPs for British airstrikes against Islamic State.

A detailed case for escalating military intervention will be set out to the Commons this week by Prime Minister David Cameron in the wake of the murders of 130 people on the streets of Paris by the Islamist extremists.

Mr Cameron will visit the city tomorrow for talks with president Francois Hollande - as attention switched to the Belgian capital Brussels which is in lockdown as the manhunt continues for one of the attackers.

The Chancellor declined to be drawn on reports that a vote could be held within weeks but said he believed the atrocities - and unanimous United Nations Security Council backing for countries to take "all necessary measures" - were swaying the argument.

Any vote against allowing the RAF - currently bombing only in Iraq - to target IS over the border in Syria would be "a publicity coup" for the jihadists, he told BBC1's Andrew Marr Show.

Ministers say there will be no vote until they are confident of the support of sufficient opposition MPs to demonstrate a clear parliamentary will.

"This week we are going to step up our diplomatic efforts, our humanitarian efforts and make the case for a greater military effort against Isil," Mr Osborne said.

"The Prime Minister will seek support across Parliament for strikes against that terrorist organisation in Syria. Frankly, Britain has never been a country that stands on the sidelines and relies on others to defend us."

Mr Cameron's case will come in the form of a response to a report by the Commons foreign affairs committee which expressed severe reservations about the coherence of the Government's case.

He will have been encouraged by the declaration of its Conservative chairman Crispin Blunt that the conditions it said were necessary to justify the action could now be met.

"It remains for the prime minister to demonstrate that our Government is properly focused on how," he wrote in The Observer.

Asked if he believed opinion had been hardened by the Paris attacks, Mr Osborne said: "I suspect that it is changing the views of those who have previously opposed Britain getting involved, and British airstrikes in Syria, but let's see.

"We are not going to go to the House of Commons and lose again. That would be a publicity coup for Isil, that would send a terrible message about Britain's role in the world.

"So we are only going to call a vote when we are confident that we are going to win.

"The UN vote in the last couple of days has shown the world that there is actually a united determination to deal with this pure evil.

"He will make the case, we'll make the case as a Government, we will allow MPs to digest that response and then we will see where we stand."

In an apparent dig at Labour leader Jeremy Corbyn he said there was no chance of persuading "those who are never going to authorise or sanction or be part of any kind of British military action abroad".

Mr Corbyn said the UN vote should be a catalyst for renewed efforts to find a political solution in Syria, not "external intervention", but faces demands from Labour MPs not to enforce a party line against air strikes.

Dozens are reported to be ready to defy him in the Commons.

Mr Osborne said the UK had "retreated within itself for a bit" after the Iraq war, culminating in the 2013 Commons' vote against air strikes in Syria that Mr Cameron is anxious to avoid repeating.

"Now we are seeing there is a price for not getting involved," he said.

"It is very easy always to point to the cost of getting involved, including the sacrifice of British lives.

"What is sometimes more difficult to spot is the price of not getting involved."

Mr Blunt said the Paris attacks and the downing of a Russian airliner over Egypt by an IS bomb had "concentrated minds and put urgency and steel behind key international actors who have until now had irreconcilable positions on the future of Syria".

Talks over a political settlement in Syria had provided encouragement that regional ground forces could be put in place to take control of IS-held areas hit by allied air strikes - one of the key factors, he suggested.

"A month ago, we did not believe the conditions we set could be met. I now do," he wrote.

"It remains for the Prime Minister to demonstrate that our Government is properly focused on how."