Foreign embassies refusing to pay the capital’s congestion charge have accrued a bill in excess of £23 million, new figures show.

Today’s disclosure of such a high sum will fuel an ongoing battle over the £8 daily charge between Transport for London and the embassies, which claim that diplomatic immunity exempts them from paying it.

It also puts Boris Johnson and his arc-hrival Ken Livingstone in unusual agreement, with Mr Johnson vowing to continue his predecessor’s fight to recover the charge.

Mr Livingstone grew increasingly angry at the embassies’ refusal to pay, leading to his labelling of Robert Tuttle, the US ambassador, as a “chiselling little crook” in 2006.

The new figures show that the United States is still at the top of the list, with its embassy owing more than £2.7 million since the charge was introduced in February 2003.

The Russian embassy owes more than £1.8 million, while the Japanese embassy is a close third with £1.77 million.

More than 120 countries owe £1.76 million in unpaid charges, consisting of the £8 flat rate charge. Because they refuse to pay they have been charged extra penalties, with the accrued amount totalling £23.12 million.

The figures emerged in a written answer by Boris Johnson, the Mayor of London, to the London Assembly.

Murad Qureshi, a Labour member of the Assembly, described the amount as “shockingly high”.

Mr Qureshi said: “It is not for diplomats to pick and choose which rules they obey and which they don't. While they are guests here in London they should play by our rules.

“I hope the Mayor has the guts to stand up the freeloaders and ensure TfL isn't out of pocket for much longer.”

The embassies claim that they are not required to pay the charge because it is a tax from which they are exempt under the Vienna Convention governing diplomatic relations.

However TfL insists that it is a service charge which embassies must therefore pay.

Mr Johnson expressed disappointment at the refusal of the diplomats to pay the charge.

He said: “I am keen to get all embassies complying with the scheme as they should. TfL will continue to engage directly with the Foreign and Commonwealth Officer and those embassies that refuse to pay."

A spokesman for the US Embassy said that it “conscientiously abides” by all UK laws, including paying fines for traffic violations.

However he added that the “direct taxation of diplomatic missions” was prohibited under the Vienna Convention.

“Former Mayor Ken Livingstone himself admitted in 2003 that the congestion charge qualified as a direct tax,” he said.

“The embassies of over 80 countries agree that the congestion tax cannot be levied on diplomatic missions and do not pay the charge.”

The Foreign Office did not respond to inquiries by The Times but a TfL spokesperson said: "TfL and the UK Government are agreed that the Congestion Charge is a charge for a service and not a tax which means that diplomats are not exempt from payment. TfL has held discussions with the Foreign and Commonwealth Office and a number of embassies about payment of the Congestion Charge. As a result of these discussions, a number of previously non-paying embassies are now paying the Charge."

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