UEFA has officially sanctioned a new-look Champions League a day after plans for a controversial breakaway European Super League were announced.

The reforms received unanimous backing from the ECA (European Club Association) Board and the UEFA Club Competitions Committee following what UEFA described as "extensive consultation across the football family".

Under new rules which were announced on Monday, there will be 36 teams competing in the Champions League instead of 32, while the present group-stage format – whereby there are eight pools of four – will be scrapped.

Each team will instead play 10 group games before advancing to a last-16 knockout format. The changes, which have faced criticism, will be implemented for the 2024-25 season onwards.

Similar format alterations will also be applied to the Europa League, with six matches in a league stage of the competition.

UEFA President Aleksander Ceferin said: "This new format supports the status and future of the domestic game throughout Europe as well. It retains the principle that domestic performance should be the key to qualification and reconfirms the principles of solidarity right through the game and of open competition.

"This evolved format will still keep alive the dream of any team in Europe to participate in the UEFA Champions League thanks to results obtained on the pitch and it will enable long-term viability, prosperity, and growth for everyone in European football, not just a tiny, self-selected cartel.

"Football is a social and cultural treasure, enriched with values, traditions and emotions shared across our continent.  As the governing body and responsible stewards of the European game, it is UEFA's role to safeguard this legacy while leading positive future development of football in Europe for national associations, leagues, clubs, players, and fans at every level. 

"This is why we had an extensive consultation process over the last two years which led to the unanimous backing of our proposal and we are convinced that these reforms achieve those objectives."

The news comes following Sunday's announcement that 12 clubs have agreed to become founders members of a rival Super League, which has been met with widespread condemnation.

Manchester United, Manchester City, Liverpool, Chelsea, Arsenal and Tottenham from the Premier League have joined with Juventus, Milan and Inter of Serie A, and LaLiga giants Barcelona, Real Madrid, and Atletico Madrid in signing up.

Europe's top leagues vowed to do all they can to block the project and UEFA described the breakaway plans a "cynical project".

In an emphatic response, UEFA together with the English Football Association, Premier League, the Royal Spanish Football Federation, LaLiga, the Italian Football Federation and Serie A have joined forces in attempt to quell the Super League.

They reiterated a pledge to ban teams from other competitions if they take part in the Super League, while FIFA's threat of barring players from the World Cup was also alluded to.