A war of words has broken out between Fifa and top European clubs after a move that could have the number of internationals played each year slashed.

The European Clubs' Association (ECA) and Uefa have reached an agreement on proposals to change the international calendar.

But clubs are still refusing to talk to Fifa, who have the ultimate power over the number of matches.

The agreement would have an average of nine internationals played a year rather than 12, with nine double-headers over a two-year period and no one-off friendlies, such as tonight's England v Holland game, with the August friendly date scrapped.

It is a compromise solution – last year the clubs demanded the number of internationals be halved to six a year – and was announced at the ECA general assembly in Warsaw.

However, ECA chairman Karl-Heinz Rummenigge confirmed the clubs' boycott on talks with Fifa stands.

He said: "The agreement with Uefa is a major breakthrough for European club football.

"With this agreement, Uefa recognises the importance of clubs and the contribution they make to the success of national team football.

"The negotiations have not always proved easy, but were always conducted in a fair and respectful manner.

"I thank Uefa, in particular Uefa president Michel Platini, on behalf of all European clubs and look forward to our continued cooperation."

He added: "While an agreement has been reached with Uefa, the situation remains unsatisfactory in relation to Fifa.

"Discussions with the Fifa president have failed to lead to a satisfactory outcome which takes account of the clubs' demands."

Uefa also agreed to take out insurance to cover the wages of all players injured on international duty, starting at Euro 2012, and to increase the amount of money paid to clubs for their players taking part in the tournament.

The amount was €55m for the last tournament and the new figure – a "substantial increase" according to the ECA – will be announced next month.

But Fifa have pointed out that only they have the power to make changes to the calendar.

They are surprised by recent ECA comments stating they are not satisfied with their discussions with football's world governing body regarding the international match calendar.

And they state the international match calendar is applied on a worldwide basis and is regulated by Fifa.