Everton manager Frank Lampard has been charged with improper conduct by the Football Association (FA) for the comments he made after his team lost 2-0 away to Merseyside rivals Liverpool last month.

Lampard criticised referee Stuart Attwell after he did not award a penalty for a challenge on Everton's Anthony Gordon, with the manager suggesting that the spot kick would have been given if the challenge had been made on a Liverpool player.

READ | Bournemouth returns to EPL after 2-season absence

"It is alleged that the manager's comments constitute improper conduct as they imply bias and/or attack the integrity of the match referee - or referees generally - and/or bring the game into disrepute contrary to FA Rule E3.1," the FA said on Wednesday.

Lampard, whose team is in the relegation zone, has until May 9 to respond to the FA.