Hamas has thanked Jeremy Corbyn for his message of solidarity to a pro-Palestinian rally in London, a move that threatens to reignite questions over the Labour leader’s links with the militant group.

“We have received with great respect and appreciation the solidarity message sent by the British Labor Party Leader, Jeremy Corbyn, to the participants in the mass rally that took place in central London,” Hamas said in a statement.

Around 4,000 people marched in London over the weekend for Nakba Day, the annual day of commemoration for the thousands of Palestinians who were displaced from their homes during the 1948 war with Israel.

Mr Corbyn did not speak at the event but sent a message to the marchers calling on the UK government to condemn the killing of protesters in Gaza and freeze arms sales to Israel.

He also promised that if he becomes prime minister he would recognise Palestine as a state. “We cannot stand by or stay silent at the continuing denial of rights and justice to the Palestinian people,” he said.

Hamas praised Mr Corbyn for taking an “advanced moral and political position worthy of all praise and thanks”. Mr Corbyn has been dogged by questions over his connections with Hamas, which is designated as a terrorist group by the UK, US, and the EU.