No option really. Too close to the election to parachute another candidate in. Which would be suicide.
People are holding their noses and voting Labour. Many would defect to Galloway. Or just not vote.
Additionally Ali is simply repeating what the US and Egyptian governments have said. His conspiracy theory is wrong though. This time. That's the problem the Israelis have now : they are no longer getting the benefit of the doubt as their conduct in general is so appalling. I imagine this guy will be quietly stood down after the GE though.
Starmer has made a rod for his own back , everything and anything is anti semitic to get rid of Corbyn and his allies. Now it's biting him on the arse. Tough.