The UK’s former ambassador to Russia has said the diplomatic hostility between the Kremlin and the West will “erode away” within “a few months”, because both sides require a functioning relationship.

Sir Tony Brenton, speaking exclusively to The Independent, drew from his own experiences of dealing with diplomatic relations between Britain and Russia in the aftermath of the Alexander Litvinenko poisoning.

Theresa May expelled 23 Russian diplomats on 14 March in response to the poisoning of former double agent Mr Skirpal and his daughter Yulia by nerve agent in Salisbury. On Thursday the EU expressed its support for Ms May and recalled its ambassador from Moscow.

But despite the heavyweight diplomatic manoeuvring, Sir Tony believes Russian-European relations will have to return to relative normality because maintaining high-level contacts is a necessity for all parties.

During his time as ambassador 15 British Royal Navy personnel from HMS Cornwall were held captive by Iran in 2007.

It was claimed they had entered Iranian waters – an accusation the UK denied.

The sailors were released 13 days later after Sir Tony negotiated with the Russians, who had significant influence over Tehran.

Sir Tony said that if British-Russian relations had been soured beyond repair, managing the release of the personnel would have been difficult.

“Things like that happen quite regularly and at various levels we will need the Russians to help us,” Sir Tony said.

“As part of our sanctions, we are not going to have any high-level contacts with the Russians for a while. This will begin to erode in a few months because you need to have high-level contacts on things.”

Then in 2014 when Russia seized Crimea from Ukraine, the response from the West was to impose economic sanctions.

Although there was no formal method of restoring diplomatic relations, the waters were calmed when the then US Secretary of State, John Kerry, and the Russian foreign minister, Sergei Lavrov, crossed paths at a number of international conferences.

“The interesting parallel here is that the West was going to ‘isolate’ Russia after Ukraine and did so for a little bit, but this ended up eroding away,” Sir Tony said.

“These high-level freezes tend to erode quite rapidly because the world has to do its business.

“We will be slow to resume our ties, but we will in a few months’ time as we need to get back to being able to do business with the Russians.”

Although Sir Tony said he supported the actions taken by the Government, he warned that the language that had been used thus far by government ministers had been “unnecessarily virulent”.

“Obviously we have to react robustly and firmly to deal with the Skripal outrage but at some point we are going to have to get back to doing business with Russia.” Sir Tony Brenton, former British ambassador to Russia

He said in the wake of the Litvinenko poisoning there was an active effort to ensure political language was “very guarded” – an approach that has not been mirrored in 2018 by Defence Secretary Gavin Williamson and Foreign Secretary Boris Johnson.

Mr Williamson had told Russia to “shut up and go away”, while Mr Johnson compared the forthcoming World Cup in Moscow to the Olympic Games under Hitler.

Mr Johnson said it would be sickening to watch Russian President Vladimir Putin present the World Cup in the summer, in response to concerns that the event would be used as a “PR exercise to gloss over the brutal, corrupt regime”.

“Obviously we have to react robustly and firmly to deal with the Skripal outrage, but at some point we are going to have to get back to doing business with Russia,” Sir Tony said.

“We should certainly be taking action that minimises the recurrence of [a similar] attack, but we should not be burning our bridges so much that we cannot re-establish lines of communication.

“It seems to me that Gavin Williamson and Boris Johnson are dangerously close to burning those bridges.”

Defence Secretary Gavin Williamson: 'Frankly, Russia should go away, and should shut up'

The current diplomatic crisis has seen a significant escalation in tension. Sir Tony described it as the “latest manifestation” of how bad relations between the two countries had become.

He warned that confrontation had reached a point “where Putin devotes a chunk of his election speech to boasting about nuclear weapons”.

“The Russians are very proud, they know in any confrontation they would lose, but their final ace in the hole is their nuclear arsenal.

“That does not mean they want to use it or are planning to use it, but we must steer the world away from them wanting to use it.”

Vladimir Putin's Photo ops – Russia's Man of Steel? Show all 20 1 /20 Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin is pictured with a horse during his vacation outside the town of Kyzyl in Southern Siberia on August 3, 2009. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin aims at a whale with an arbalest to take a piece of its skin for analysis on the Olga Bay, some 240 kilometres north-east of Nakhodka on August 25, 2010. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin plunges into the icy waters of lake Seliger during the celebration of the Epiphany holiday in Russia's Tver region AFP/Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin (top) takes part in a judo training session at the "Moscow" sports complex in St. Petersburg, on December 22, 2010. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin works out at a gym at the Bocharov Ruchei state residence in Sochi on August 30, 2015. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin fishes in the remote Tuva region in southern Siberia. The picture taken between August 1 and 3, 2017. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin (L) and the leader of the Night Wolves biker group, Alexander Zaldostanov (R), also known as the Surgeon, ride motorcycles on August 29, 2011 at a bikers' festival in the Black Sea port of Novorossiysk, Russia. Putin described leather-clad bikers as brothers and boasted of the "indivisible Russian nation" after roaring into a biking rally on a Harley Davidson. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin wears glasses as he visits the Technology Park of the Novosibirsk Academic Town in Novosibirsk on February 17, 2012. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin rides a horse during his vacation outside the town of Kyzyl in Southern Siberia on August 3, 2009. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin holds a pistol during his visit to a newly-built headquarters of the Russian General Staff's Main Intelligence Department (GRU) in Moscow, 08 November 2006. ?Some countries are seeking to untie their hands in order to take weapons to outer space, including nuclear weapons,? Putin said at the Chief Military Intelligence Department on Wednesday. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin sits inside a T-90AM tank during a visit to an arms exhibition in the Urals town of Nizhny Tagil on September 9, 2011 Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin wears a helmet and the uniform of the Renault Formula One team before driving a F1 race car on a special track in Leningrad region outside St. Petersburg on November 7, 2010. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin guides a boat during his vacation in the remote Tuva region in southern Siberia. The picture taken between August 1 and 3, 2017. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin hunts fish underwater in the remote Tuva region in southern Siberia. The picture taken between August 1 and 3, 2017. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin is seen at the Russian boxing team training club after casting his vote for the Russian Presidential election, 14 March 2004 in Moscow. Putin coasted to a landslide victory with 69.0 percent of the vote in Sunday's election, according to the first exit poll aired on Russian television moments after voting ended across the country's 11 time zones. AFP/Getty Images Vladimir Putin's Photo ops – Russia's Man of Steel? Russian President Vladimir Putin poses for a picture inside the Tupolev-160 strategic bomber jet at the Moscow's Chkalovsky military airport, 16 August 2005. President Vladimir Putin took off from Moscow for a supersonic flight in a cruise-missile carrying Tupolev-160 bomber jet, the latest in the Russian leader's action-packed public appearances. After a health check, Putin donned a flight suit and took the commander's position in the strategic bomber, which was piloted by Major General Anatoly Zhikharev, with a colonel and a lieutenant colonel in charge of navigation, Russian media reported. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? A picture released on March 6, 2010 shows Vladimir Putin look through binoculars in the Karatash area, near the town of Abakan, during his working trip to Khakassia, on February 25, 2010. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin measuring a polar bear on the island Alexandra Land, part of the Franz Josef Land archipalego in the Arctic Ocean. Putin, better known in the West for his tough-guy image, expressed concern for the fate of Arctic polar bears threatened by climate change. "The polar bear is under threat. Their population is currently only 25,000 individuals," Putin was quoted by Russian news agencies as saying Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Vladimir Putin carries a hunting rifle during his trip in Ubsunur Hollow Biosphere Reserve in Tuva Republic in this undated picture released on October 30, 2010 by RIA Novosti news agency. Getty Vladimir Putin's Photo ops – Russia's Man of Steel? Russian President Vladimir Putin pilots a motorized hang glider while flying with cranes as he takes part in a scientific experiment as part of the "Flight of Hope", which aims to preserve a rare species of - cranes on September 5, 2012. At the helm of a motorized hang glider that the birds have taken as their leader, Putin made three flights - the first to get familiar with the process, and two others with the birds. AFP/Getty

As diplomatic relations have soured Dmitry Peskov, Mr Putin’s spokesman, said that Russia “doesn’t understand” the decisions that have been taken.

The Kremlin said the UK was forcing its allies to take “confrontational steps” over the incident and denied any involvement in the poisoning.

Russia said it would evaluate the situation and actions taken by the West before responding.

Mr Peskov said: “We don’t know what info the UK had when it discussed with EU colleagues. We don’t understand it.