Manchester United and Manchester City are angry over the Premier League vote for the change of transfer deadline.
One Premier League executive condemned the move as "like Brexit" and said the decision handed an advantage to rivals, particularly in Spain, says the Daily Mail.
Five clubs — Manchester United, Manchester City, Crystal Palace, Swansea and Watford — voted against, while Burnley abstained.
Agents have warned that their decision could drive prices up with the rest of Europe now aware that England will have to get its business done early. Indeed they say it will leave clubs susceptible to offers from abroad and with no ability to replace outgoing stars.
The likes of Spain's La Liga are not set to follow the Premier League's lead.