David Cameron insisted last night that British military intervention in Syria would help secure a political settlement as the RAF carried out another mission.
But the prime minister was under renewed pressure over the claim 70,000 moderate Free Syrian Army fighters would be able to take on Islamic State on the ground.
At the same time, opposition forces in the country argued the UK action “will not make a big difference”, while Bashar al-Assad’s regime denounced it as “noise and propaganda”.
Nato secretary general Jens Stoltenberg said Britain’s involvement would be an important contribution to downgrading IS, however.
And former PM Tony Blair welcomed the move, warning a continued failure to recognise the scale of the challenge would lead to terrorist attacks “potentially worse than those in Paris”.
Mr Cameron faced suggestions Ministry of Defence officials had warned about using the 70,000 figure in his statement to the Commons last month.
But yesterday a Number 10 spokeswoman rejected the claim concerns had been raised, adding: “The 70,000 figure was produced by the joint intelligence committee, which includes in its membership officials from the MoD.”
SNP Westminster leader Angus Robertson said there was “absolutely no evidence whatsoever” they would deploy as a unified army and questioned how moderate some of them are.
The Moray MP added: “David Cameron’s reliance on this figure is all too reminiscent of Tony Blair’s totally discredited claims in the dodgy dossier of 2003 that the UK was just 45 minutes from attack by Iraqi weapons of mass destruction.
“What we’ve seen from the prime minister is wishful thinking … Quite simply the case for bombing Syria has not been made.”
But Scottish Secretary David Mundell said he did not accept the “dodgy dossier” comparison.
He said: “These issues were fully debated in parliament.
“I think everybody knows there are differences between the forces on the ground in Syria.
“I don’t think it could be suggested that anybody who voted in the House of Commons did so without having fully understood the issue around these numbers.
“It is completely different from 2003 when people relied on information Tony Blair provided, which proved to be inaccurate.”
The MoD confirmed two Tornado fighter jets flew an armed patrol over the east of the country “gathering intelligence on terrorist activity” during Thursday night.
In a continuation of operations in Iraq, two Tornados also “silenced” a “terrorist” sniper team with a “direct hit” from a Paveway IV guided bomb, it added.
During a visit to Bulgaria, Mr Cameron said: “Bringing everyone around the table and trying to get a political settlement is absolutely crucial but we can’t wait for that to happen before we start taking action against Daesh.
“The strikes actually help to bring about a political settlement,” he added. “The political process and the action against Daesh to keep us safe at home go hand in hand.”
Meanwhile, the German Parliament approved a £96million non-combat mission in support of coalition forces.
The country will send up to six Tornado reconnaissance planes, a tanker aircraft and a frigate to help protect the French aircraft carrier, but will not actively engage in combat.
Up to 1,200 soldiers will serve as support troops in Turkey and elsewhere, including at headquarters operations in Qatar and Kuwait.
As news of the German commitment emerged, Home Secretary Theresa May warned an EU-wide deal on sharing air passenger records must be struck immediately in light of the Paris attacks.
She also said more action was needed to halt the flow of firearms as she arrived for talks with European counterparts in Brussels.
Back home, Jeremy Corbyn enjoyed a moment of respite from Labour’s internal wrangling over air strikes in Syria after the party triumphed in the Oldham West and Royton by-election.
Jim McMahon won the seat, vacated by veteran Michael Meacher’s death, with a majority of more than 10,000 and an increased share of the vote.
But Ukip leader Nigel Farage has insisted the contest was “bent” and announced his party would file a formal complaint.