The Argentinian midfielder played a key role in his country's 2022 World Cup win and scooped the competition's best young player award.

Fernandez, 22, will make the move from Portuguese side Benfica.

The deal breaks the previous record of £100m, paid by Manchester City to Aston Villa for England star Jack Grealish in August 2021.

It means Chelsea have now spent more than £300m on transfers in January, including securing an £88.5m deal for Ukrainian forward Mykhailo Mudryk.

Fernandez was left out of Benfica's squad for their game against Arouca on Tuesday night - and underwent a medical in Portugal ahead of his switch to Stamford Bridge.

According to Portuguese broadcaster SIC, Fernandez will fly to the UK this morning, with a private jet scheduled to leave Lisbon airport at 10.20am.

Fernandez will help to replace Jorginho, who joined Chelsea's London rivals Arsenal on Deadline Day in a £12m deal.

This is the biggest deal in the history of British football - and Chelsea have spent more money on transfers than all the other clubs in the major European leagues put together: Germany, Spain, Italy and France.

Overall, Chelsea have spent almost £600m on new players since a recent change of ownership.