Sadiq Khan is “heartbroken” and “angry” for the 17 people deported on a flight to Jamaica this morning.

The mass-deportation shuttle left Britain at 6.30am, despite a last minute court battle to stop take off.

But campaigners blocked 25 detainees from boarding, arguing they did not have access to legal advice.

All those due to board the flight hold Jamaican citizenship, and have been convicted of crimes with jail sentences of a year or more in the UK.

Some prisoners committed serious violent crimes – including rape and manslaughter – but others are non-violent drug offenders.

Many of those due to be deported came to the UK as children, and have never returned to Jamaica.

Campaigners argued that a broken O2 phone mast prevented prisoners from getting mobile signal and speaking to their lawyers.

An eleventh hour ruling from the Court of Appeal last night said those held at Harmondsworth and Colnbrooke detention centres, near Heathrow, could not be deported because of phone problems.

The court said anyone who had not had access to a phone with a non-O2 sim before February 3 must remain in the country.

The Government claims it’s not responsible for a hostile environment, but the evidence demonstrates it’s not true

Prominent politicians including Labour’s David Lammy and Shadow Home Secretary Diane Abbott urged the Home Office to reconsider the flight.

And more than 150 MPs wrote to Boris Johnson asking him to cancel take off.

Campaigners say the Government has not learned lessons from the Windrush scandal, which saw Brits invited to the UK from Commonwealth countries after World War Two threatened with deportation.

But the Kingston-bound flight went ahead this morning with 17 convicts held at Brook House detention centre, near Gatwick, on board.

Speaking to the Local Democracy Service today, the Mayor described the deportations as “an outrage”.

He said: “You’ve got British people – and they are British – who are being deported to a country many of them don’t know.

“The Government claims it’s not responsible for a hostile environment, but the evidence from this fiasco of those who are being deported to the West Indies demonstrates it’s not true.”

He added: “I think what the Government should be doing is pausing this and getting some clarity – but also addressing the concerns people have.

“If you look at the history of the Windrush generation, they came here because they were invited to do so after the Second World War.

“Literally to help rebuild our country, to staff the NHS, to staff London transport, to staff the really important jobs that needed to be done.

“And low and behold because they didn’t regularise their documentation, because they didn’t go through the loops and overcome the hurdles they’re now being deported back to a country many of them haven’t been to in many many decades – it’s an outrage.”

A spokesperson for the Home Office said: “We make no apology for trying to protect the public from serious, violent and persistent foreign national offenders.

“The court ruling does not apply to all of the foreign national offenders due to be deported and we have therefore proceeded with the flight.”