Boris Johnson visited Yorkshire yesterday - five days after a deluge of floods forced people from their homes.
But he was given the cold shoulder by many residents, who felt his intervention was too little too late.
Now, assurances have been sought on how the same level of devastation can be prevented in the future.
Dan Jarvis, the Sheffield City Region metro mayor and Labour candidate for Barnsley Central, said he spoke to the Prime Minister after Tuesday's Cobra meeting on the issue, and would be writing to him to set out what was needed for South Yorkshire.
This includes a review by the Environment Agency of the River Don and local flood defences, which Mr Jarvis said were "not sufficient".
Mr Jarvis said he was concerned about what was coming later in the week, with more rain forecast for South Yorkshire.
But he said: "One concern is that this doesn't get forgotten about. The situation is such that we will be dealing with this for years to come.
"I will be talking about the need for urgent support in the short term and then getting quite quickly onto what needs to be done in the medium term."
He said one of the key lessons from 2007, when there was widespread flooding in Sheffield and Doncaster, was the need to get the key local and national organisations together once the immediate response is concluded.
Mr Jarvis said he hoped this would take place in the next two weeks and had received assurances from the Prime Minister that he would send a government representative.
He said: "There is a huge amount of investment that is going to be required in a number of areas and we need to capture where that investment is going to be required.
"There is quite significant disruption to our transport infrastructure. We are going to have a big bill to repair some of the damaged roads and transport infrastructure to get it up and running as soon as possible."
Speaking to The Yorkshire Post yesterday Boris Johnson insisted the Government had been working “round the clock” to help those impacted by devastating floods in places like Fishlake, South Yorkshire.
But when pushed on whether he would now describe the situation as a national emergency, he still declined to do so.
Mr Johnson praised the emergency services response and the communities which had stepped in to help, but he said he did not recognise Labour analysis which claimed spending on environmental protection had been cut by 14 per cent in Yorkshire between 2016/17 and 2017/18, while it had risen by 14.5 per cent in the South East.
He said: “I don’t recognise those figures at all because the figures I’ve seen show it’s £699 a head in this part of the world and something like £400 in the South, it varies across the country.”
He added: “This Government has invested more than the previous Labour government [in flood defences].”