Because they are doing precisely the same thing.
The attack came after the Labor leader announced a visit to South Wales to meet communities affected by Storm Dennis, meet residents and support relief and recovery work.
Ahead of the visit Mr Corbyn set out words criticising the government's refusal to convene a COBRA meeting and Boris Johnson's failure to visit any of the affected areas.
He contrasted it with Mr Johnson's visit during the period of flooding during the election campaign last year.
Mr Corbyn said that Boris Johnson’s absence and failure to convene COBRA to help affected communities shows his “true colours” and sends a “very clear message” that the Prime Minister “simply does not care about helping communities affected by flooding” if he is not campaigning in a General Election.
He also highlighted the concerns of communities who have been “badly let down time and time again”.
He's certainly not the first or only person to criticise the government's response with some of the loudest criticism unsurprisingly coming from those directly affected.
Today Sky interviewed one man who voted for Boris Johnson but who said the PM needed to come and sort it out.
And he laughed at the offer of £500 from the Government saying: "£500? What's that going to do? There's £500 worth of damage to the freezer and the fridge".
And the Tories responded by sending out their own political attack.
George Eustice MP, Secretary of State for Environment, Food and Rural Affairs, who said: “ Jeremy Corbyn shouldn’t be trying to politicise the floods, he should be backing the government’s move to support and work with emergency personnel who are working tirelessly to help everyone affected.
“We are investing £2.6 billion in flood defences, which have already protected 200,000 properties that would otherwise have been caught out by flooding. We know there is more to do – which is why our manifesto committed us to an additional £4 billion for flood defences and today we’ve set out new measures to help the communities directly affected.”