Boris Johnson has told the football authorities that he is prepared to introduce new legislation to prevent the formation of a European Super League.

At a meeting with the FA and the Premier League, the Prime Minister voiced his “unwavering support” for their efforts to block the so-called Big Six clubs of the English game going ahead with the new breakaway competition.

Mr Johnson told the virtual meeting that the Government should “drop a legislative bomb” to prevent the proposal going ahead as planned, sources said.

“No action is off the table and we are exploring every possibility to ensure these proposals are stopped,” the Prime Minister said after the meeting.

Downing Street said he expressed “solidarity” with the fans’ groups, who were also represented at the meeting, saying they should be at the heart of any decisions about the future of the national game.

“The Prime Minister confirmed the Government will not stand by while a small handful of owners create a closed shop,” a No 10 statement said, adding that he was clear “legislative options” are among those being explored.

Labour leader Sir Keir Starmer said the party would back any legislation the Government brought forward to prevent the Super League going ahead.

“This is about willpower now. If the Government is determined to do something about it we will back them. There is no block in Parliament to action if action is needed,” he said.

Chief executive of the Football Supporters’ Association, Kevin Miles, said Mr Johnson made clear at the meeting he would be prepared to use legislation to protect the authorities from legal action if they moved against the breakaway six.

Mr Miles said that the rule books of the FA and Premier League, which were represented by chief executives Mark Bullingham and Richard Masters, give them the power to exclude clubs from their competitions but they may then face legal challenges under competitions law.

“The mood music from the Government was they would do what was required to make sure that the measures to exclude those clubs from competitions would not fall foul of competition law, and that they would amend the law if necessary,” he told BBC Radio 4’s World At One.

The meeting came as the Competition and Markets Authority (CMA) said it would be “carefully considering” the proposals which have caused outrage throughout the sport.

The Prime Minister’s official spokesman later told reporters that among the measures under consideration was preventing players of the clubs involved getting work visas and the withdrawal of police funding for match days.

“All these options are on the table at the moment,” the spokesman said.

Lib Dem leader Sir Ed Davey suggested a new law requiring owners to ballot season ticket holders before committing clubs to newly formed competitions, as he demanded “real action” from the Government.

The Commons Digital, Culture, Media and Sport Committee will hold a session on the proposals.

Committee chairman Julian Knight said “no one will be off limits” when the MPs look at how to safeguard the sport.

“We are in discussion with key players and will want to hear from major stakeholders as the impact of the new European Super League proposals unfold,” he said.

There were protests outside grounds around the country on Monday at the scheme put forward by Liverpool, Manchester United, Manchester City, Chelsea, Arsenal and Tottenham, together with six leading Spanish and Italian clubs.

Fans of both Liverpool and Leeds gathered outside the Yorkshire club’s Elland Road stadium before their evening fixture while a plane flew overhead with a banner proclaiming “Say No To Super League”.

The plan has been roundly condemned by both the FA and the Premier League, while Uefa president Aleksander Ceferin has warned players who take part could be banned from representing their countries in the World Cup and Euros.

However, the Super League chairman Florentino Perez – who is the president of Real Madrid – insisted the proposals were necessary to enable the sport to “evolve” in the wake of the coronavirus pandemic.

“When you don’t have income beyond television, the way to make it profitable is to make more attractive matches. That’s how we started working,” he told Spanish TV in his first public comments since the plan was announced at the weekend.

The 14 top-flight teams in England not involved “unanimously and vigorously” rejected the Super League during an emergency meeting with the FA and Premier League on Tuesday.

“The Premier League is considering all actions available to prevent it from progressing, as well as holding those shareholders involved to account under its rules,” a statement added.

Labour’s shadow minister for sport Alison McGovern urged the CMA to investigate the plans, saying: “Proposals for a breakaway league are nothing short of an attempt to stitch up competition for a few elite clubs at the top.”

A spokeswoman for the regulator responded: “The proposals for a European football Super League have attracted high levels of public interest. It is a complex area and we will be carefully considering any competition concerns relating to these proposals.”

The plan – which also includes the Spanish sides Atletico Madrid, Real Madrid and Barcelona, and Italian clubs AC Milan, Juventus and Inter Milan – has support from investment bank JP Morgan, which will provide debt financing for the competition.

It is understood it will underwrite around six billion US dollars (£4.3 billion) in loans for teams involved.

It would see the breakaway teams create a competition to rival the Champions League but it would not feature relegation or promotion.

Teams would play each other in midweek while still competing in their domestic leagues.