Jeremy Corbyn has insisted there is “no equivocation” over his attitude to Russia’s actions in Syria after criticism from the husband of former Batley and Spen MP Jo Cox.
Mr Corbyn defended Labour’s position as he visited the constituency to campaign in the by-election triggered by Mrs Cox’s death earlier this year.
Brendan Cox had earlier this week branded comments from Mr Corbyn’s spokesman, Seamus Milne, apparently comparing the actions of Russia in Syria to those of the United States as “absolutely disgraceful.”
Several Labour backbenchers have also expressed concern that the party has not been clear enough in its condemnation of Russia.
Mrs Cox was co-chairman of the Friends of Syria group of MPs and had nominated volunteer rescue workers in the country for the Nobel Peace Prize.
Mr Corbyn said: “There is no equivocation, the bombing in Syria is wrong by all sides.
“The bombing by the Russians of the UN aid convoy was absolutely wrong and should be investigated for the crime it was.
“The solution has to be a political one, there has to be a reconvening of the Geneva conference immeditely, there has to be an immediate verifiable ceasefire.”
He added: “If there is any misunderstanding it is not on my part because I am very clear that the war is appalling.
“It has created millions of refugees. It has killed hundreds of thousands of people and created devastation across the whole region.
“At the end of the day every war has to be ended by a political settlement. I want that ceasefire as quickly as possible.”
Labour has chosen actress and screenwriter Tracy Brabin to contest the Batley and Spen by-election which takes place next Thursday.
None of the other major parties are fielding candidates out of respect for Mrs Cox who was killed in her constituency in June although several fringe parties are taking part.
Mr Corbyn said: “This is obviously a by-election nobody wanted and it is an unbelievable tragedy, the death of Jo and the manner of the death of Jo.
The other major parties decided out of respect not to contest the election and so it is a plethora of right wing candidates and Tracy.
“I’m very confident Tracy’s going to be elected. I hope that there’s going to be a good turnout. I hope people come out and support Tracy because she’s a brilliant candidate but also support Tracy it’s an expression of our democratic will.”
Batley and Spen is among the Labour-held seats that have seen a rise in support for the UK Independence Party in recent years.
The trend, which saw Ukip secure more than 9,000 votes in the constituency at last year’s general election, has spurred some Labour activists and MPs to call on Mr Corbyn to take a clearer line on controlling immigration.
But he has focused on measures to help communities cope better with inward migration and to prevent employers using migrant workers as cheap labour.
Mr Corbyn said: “The issues are about investment in public services, a growing economy to invest in jobs, and also prevent undercutting by companies bringing in low paid workers to undercut local pay and conditions service and that will actually make a difference to the number of people coming.”
Asked if he wanted to see fewer people coming to the UK, the Labour leader said: “I want to see an end to the undercutting which is the main motive for people coming in from the European Union, particularly from Eastern Europe and the companies that are doing it are grossly exploiting people and I think that will a very big difference to the numbers indeed.”