The Prime Minister has welcomed the intended departure of two English football clubs from the controversial new European Super League, and urged others to “follow their lead”.

Boris Johnson tweeted his comments as plans for the recently announced new competition began coming apart on Tuesday evening.

Initial reports indicated Chelsea were to back out of the proposed new league, with the Blues understood to be preparing documents to formally withdraw.

Manchester City later confirmed their intention to pull out, with the club saying in a statement it had “formally enacted the procedures to withdraw”.

Tweeting before City’s announcement, Mr Johnson said: “The decision by Chelsea and Manchester City is – if confirmed – absolutely the right one and I commend them for it.

“I hope the other clubs involved in the European Super League will follow their lead.”

The latest developments come after the Prime Minister warned that he was prepared to legislate to block the controversial new league plans, accusing breakaway football clubs of forming “a kind of cartel”.

On Twitter, Labour leader Sir Keir Starmer welcomed Chelsea’s move and urged other clubs to “follow suit”.

He tweeted: “But let’s not lose the energy of the last few days – this must be a watershed moment, where we change our game to put fans first again.”

Meanwhile, there have also been reports that Spanish clubs Atletico Madrid and Barcelona were set to withdraw from the competition.

Chelsea fan Dan Silver told the PA news agency: “I’m absolutely delighted that common sense has prevailed.”

“I think it’s great that Chelsea were first to come out and say they would leave,” he added.

“This is by far the best decision for the future of the beautiful game.

“No one should ever underestimate football fans again.”

Hundreds of Chelsea fans who had gathered outside Stamford Bridge on Tuesday to protest against the plans to join the league cheered when they heard the club was preparing to withdraw.

One unnamed fan said: “The fans have won.”

The Chelsea Supporters’ Trust (CST) said the club’s reported withdrawal was “a victory for the supporters” and claimed the positions of several board members were now “untenable”.

Tom Greatrex, the vice-chair of the Football Supporters’ Association, told the PA news agency: “It’s a spectacular miscalculation (by the clubs involved).

“If this was an attempt to gain leverage, I think they underestimated the collective will of those who love football, play football and are involved in football and assumed wrongly that that could be overridden by financial interests.”

The Football Association (FA) welcomed the news that some clubs had decided to withdraw their support for the new league, highlighting that “the game has been unanimous in its disapproval of a closed league”.

It said the proposals “could have divided our game; but instead, it has unified us all”.

The FA’s statement added: “We would like to thanks the fans in particular for their influential and unequivocal voice during this time, holding true the guiding principles of football. It is a powerful reminder that the game is, and always will be, for fans.”

The Duke of Cambridge earlier held talks on the issue with the FA’s chief executive Mark Bullingham.

It follows William, the FA president, tweeting how he shared “the concerns of fans” over the proposals.

There was ongoing anger in the football community earlier on Tuesday over the actions of the so-called Big Six English clubs, with the Prime Minister telling the football authorities he was ready to “drop a legislative bomb” if necessary.

In a morning conference call with the FA and the Premier League, he indicated the Government could act to ensure they did not fall foul of competition laws if they imposed sanctions on the clubs involved.

Speaking later at a Downing Street press conference, he said he was determined to prevent historic clubs being “dislocated” from their towns and cities and turned into “international brands and commodities” by billionaire owners without any say for the fans.

He said: “How can it be right to have a situation in which you create a kind of cartel that stops clubs competing against each other, playing against each other properly, with all the hope and excitement that gives to the fans up and down the country?

“I think it offends against the basic principles of competition.”

Mr Johnson said legislation was an option, but added: “What we want to do first of all is back the FA, back the Premier League, and hope that we can thwart this proposal before it goes very much further.”

Under the plan unveiled at the weekend, Liverpool, Manchester United, Manchester City, Chelsea, Arsenal and Tottenham would join six leading Spanish and Italian clubs to set up an alternative competition to the European Champions League.

The proposal attracted particular ire as there would be no relegation from the Super League, regardless of how well clubs do on the field, although five of the best performing teams from outside the league would be invited to participate each year.

It led to calls for the clubs involved to be expelled from the Premier League amid suggestions their players could be barred from representing their countries in the World Cup or the European Championship.

Football Supporters’ Association chief executive Kevin Miles, who was also on the conference call with No 10, said Mr Johnson had made clear he would be prepared to use legislation to protect authorities from legal action if they moved against the breakaway six.

Mr Miles said the rule books of the FA and Premier League give them the power to exclude clubs from their competitions but they may face legal challenges under competition law.

His organisation later tweeted on Tuesday evening: “On the ropes. Over before it began? #NoToSuperLeagueGreed”

The Prime Minister’s official spokesman earlier said they were also considering preventing players of the clubs involved getting work visas and the withdrawal of police funding for match days.

Sir Keir previously said his party would back any legislation the Government brought forward to prevent the Super League going ahead.

The Competition and Markets Authority (CMA) said it would be “carefully considering” the proposals following a request from Labour to investigate.

At an emergency meeting with the FA and Premier League, the 14 top-flight teams in England not involved “unanimously and vigorously” rejected the scheme.

The Premier League said in a statement it was “considering all actions available” to prevent the new league from progressing.

Real Madrid president Florentino Perez earlier insisted the proposals were necessary to enable the sport to “evolve” after the coronavirus pandemic.