The ex-British Ambassador to Syria has accused the Foreign Office of lying over the country’s civil war and said British policy there has "made the situation worse".

Peter Ford said the Whitehall department led by Boris Johnson and Philip Hammond before him had "gotten Syria wrong every step of the way", and was now falsely claiming Bashar Assad could not control the country when he is "well on the way to doing so".

It comes after the Syrian army reported that it had taken full control of Aleppo following weeks of heavy bombing and fighting in and around the city.

Mr Ford, who was Britain's ambassador to Syria from 1999 to 2003, claimed that the UK had misread and misrepresented the situation in the country since the start of the conflict.

He said: "The British Foreign Office to which I used to belong, I’m sorry to say has gotten Syria wrong every step of the way.

"They told us at the beginning that Assad’s demise was imminent. They told us he’d be gone by Christmas. They didn’t say which Christmas, so they could still be proven correct.

"But then they told us that the opposition was dominated by these so-called moderates. That proved not to be the case and now they're telling us another big lie – that Assad can’t control the rest of the country. Well I’ve got news for them – he’s well on the way to doing so."

Mr Ford said that when the conflict started the UK should have either "put everything, including our own forces on to the battlefield, or if in our judgement – as it would have been my judgement – that was not realistic, refrain from encouraging the opposition to mount a doomed campaign."

He claimed the UK’s tough talk on one hand, followed by little action to back rebels in Syria on the other had preceded a rebellion that had "only led to hundreds of thousands of civilians being maimed and killed".

Interview with Syrian mother of killed children

"We have made the situation worse."

He added: "It was eminently foreseeable to anyone who was not intoxicated with wishful thinking."

In a statement last night the Syrian army said it had "returned security to Aleppo" and called it a "crushing blow" for rebels.

The International Committee of the Red Cross confirmed "all civilians who wished to be evacuated have been, as well as the wounded and fighters".

Mr Johnson said after a meeting in Paris earlier this month that there could be no military solution to the war in Syria, while the UK has consistently taken the line that Assad cannot be a part of Syria’s future.

A Foreign Office spokesman said: "The UK continues to believe in a Syrian-led political settlement. A political solution and transition away from Assad is the only way to end the suffering of the Syrian people. The Assad regime has the blood of hundreds of thousands on its hands. There is no way it can unite and bring stability to Syria.