The Syrian foreign ministry has sent two letters to United Nations chiefs objecting to "brazen standpoints" taken by British officials and accusing Britain of a "colonialist" agenda, according to State news agency SANA.

It comes after Chancellor George Osborne acknowledged that a comprehensive plan was needed to tackle the refugee crisis "at source".

He has said that means dealing with the "evil" regime of Syrian president Bashar al Assad as well as the militant jihadists of IS.

And, speaking on BBC1's The Andrew Marr Show, he described the UK's rejection of a previous vote on military intervention in Syria in 2013 as "one of the worst decisions the Commons has ever made."

However, several opposition politicians have said they are wary about the prospect of military action.

Scotland's First Minister Nicola Sturgeon told the Sky's Murnaghan programme she is skeptical about the "efficacy" of airstrikes, given the complex nature of the conflict in Syria.

"I believe the only long-term sustainable solution here, not that it is easy or that it can be delivered quickly, is a political and diplomatic one," she said.

Her comments were echoed by Yvette Cooper who asked where the global diplomatic effort had been in getting world powers together to address the conflict.

An estimated quarter of a million people have been killed during Syria's four-and-a-half year conflict and a further 11 million have fled their homes.

it is understood that the Government is currently preparing to accept at least 10,000 people from camps on the Syrian border.

The Prime Minister has announced that the UK will take "thousands more" refugees, following fierce public pressure over the UK's response to the refugee Chancellor George Osborne acknowledged that a comprehensive plan was needed to tackle the refugee crisis "at source"

crisis, although he is yet to announce an official figure.

Number 10 is keen to demonstrate that, given stinging criticism from elsewhere in the EU, the UK is "pulling its weight."

According to Mr Osborne, Britain will fund the influx by dipping into its international aid budget.

Some of the UK's £12bn-a-year foreign aid budget will now be offered to local councils to help them house refugees at home, he said.

David Cameron will be pressed on precisely how many refugees the UK will take and what support local authorities will receive when Parliament returns on Monday.

Labour contender Yvette Cooper welcomed the Government's promise to help those fleeing persecution in Syria.

But she said the UK should not take refugees exclusively from camps on the Syrian border and should also house those who have already made it to Europe.

She also called for more to be done to help the vast number of unaccompanied Syrian children, saying the UK should bring back its "tradition of compassion and support" seen during the Kindertransport rescue effort in the Second World War.

Labour leadership contender Liz Kendall was more scathing in her criticism of the Government's handling of the refugee crisis, accusing the Prime Minister of making the UK look "uncaring and impotent" when compared to other EU countries like Germany, which is expecting some 800,000 asylum applications this year alone.

She urged the Government to accept tens of thousands, rather than thousands of refugees.

Both Yvette Cooper and Nicola Sturgeon said they would accept Syrian refugees into their own homes as part of a wider housing initiative.

MPs will get the chance to debate the refugee crisis further at an SNP opposition day debate on Wednesday.