Sadiq Khan
The London mayor's comments are a challenge to Keir Starmer as well as Rishi Sunak.
The UK will only pay France around £9million more than under the previous deal.
The mayor of London said Labour is a "government in waiting" and should adhere to collective responsibility.
'It’s probably the end of my career when I say I agree with George Osborne,' the Mayor of London joked.
UK's hottest day on record was a "game changer".
Major incident declared in the capital – as well as Leicestershire, South Yorkshire and Suffolk – as hundreds of firefighters battle blazes fuelled by heatwave.
"What we want to see is a brave generation of politicians in parliament now, tackling climate change and air quality," the mayor of London said.
Scandals including the murder of Sarah Everard and the strip search of Child Q have blighted the UK's largest force.
A spokesman for the mayor of London said: “The prime minister is wrong – plain and simple."
Keir Starmer has said he will quit if Durham police fine him for breaching lockdown rules.