The man behind the mascot, Jerry Quy, was let go by the Gunners after 27 years , with the team stating the financial impact of the coronavirus pandemic.
However, the team’s midfielder Mesut Ozil has since offered to pay the Mr Quy’s salary .
A spokesman for the Labour leader said: “Keir is a passionate supporter of Arsenal and he was disappointed by the club’s decision.
“Football is our national sport and all football clubs should send messages of solidarity – particularly to people during this difficult time.
“Keir believes people will take a dim view of clubs that are spending millions of pounds on transfers on the same day they are making hardworking staff redundant.”
Asked about Mr Ozil’s actions, the spokesman replied: “He does applaud him and he thinks that’s the kind of message footballers should be sending.”
He added: “All football clubs, particularly those wealthier clubs, should be showing how they are supporting their staff but also how they are supporting lower league clubs at the bottom.
“Football clubs do need to demonstrate the values that have come out so strongly during this pandemic which is compassion, decency and fairness. We hope all the clubs take this on board.”
Asked if he would like to go back to the Emirates this season, the spokesman replied that he would “love to” when it is safe to do so.