If we need an argument for city mayors, Marvin Rees is, in theory, it. He is a slick politician, articulate, and – fresh from a TedTalk on how cities tackle climate change – is equally comfortable speaking for Bristol locally, nationally and on a global platform.

That said, it's not all going as smoothly as he may have hoped. Last month the people of Bristol voted to scrap the City Council's mayoralty – although not until he has finished the final two years of his term.

And his climate change keynote was somewhat marred by a furore over his decision – one he said was forced on him by TedTalks' policy – to fly to Toronto to speak.

It may be a criticism he will have face again. In his new role as Core Cities UK chair, Mayor Rees tells The MJ his first job is to ‘strengthen the relationship between the UK's cities' – and he even takes some responsibility for holding the union together – and to build relationships with international cities.

He is, he says, ‘looking at the future of UK cities'. The group has launched a piece of research based around three questions to get a ‘proper, evidence-based understanding' of what they need to achieve.

The questions are: what are cities and what is their relationship to the wider geography?; what do we need our cities to be and what is their role in the UK, economically, culturally and politically?; what is the difference between where cities are now and where we need them to be in 2050, and how do we get them there?

There are, Mayor Rees explains, a huge number of challenges facing urban areas right now. We have seen rapid urbanisation, a trend that is likely to continue, and while it is great news for cities, it presents its own issues – not least that of climate change.

A cost of living crisis puts ‘making sure people have enough to eat all the time' at the top of the agenda. And he describes the growing ‘social fragility', with a lack of positive political engagement, as a major concern for cities.

‘We have to meet the needs of our growing populations in the context of the climate emergency,' he says. ‘Housing, feeding [city residents]… that goes to the heart of the challenge. We know what the challenge is, so how do we get systems around cities to meet those challenges?'

The current policy and finance system is, he suggests, not set up in a way that makes resolving these issues easy, but ‘cities might be the best vehicles we have to tackle those challenges'.

In Bristol, his focus is on homes. ‘I say repeatedly, building the right kind of homes in the right places is the single biggest tool we have to tackle inequality.'

But it is not just the council, he says, it is ‘understanding that no single person or single organisation' can go it alone that is important. Instead it is a collective of health, local government, faith groups – his list goes on – that need to work in alignment.

Even with the best will in the world from all the partner organisations, he adds, cities need investment – but there is no lack of money available. ‘Unless we get on top of the finance and open the finance for the trillions of pounds floating around the world…we will be stuck,' he says.

It's not a begging bowl to central government, it is working on the global stage to attract investment to UK's cities, to make them fit for the future. And he is keen to shift the relationship with Westminster and Whitehall, particularly on funding.

‘Throwing your cities into competition between each other, that's not a plan,' he says. ‘We need a plan to maximise our funding.'

He admits to a little healthy rivalry among the Core Cities – a ‘reluctant competition' but he adds: ‘I don't want to flourish because I made Cardiff lose.' Instead, he wants to see investment flowing, levelling up all our UK cities and he suggests: ‘I think the UK needs another conversation about mayors – and we need to think about what form of local government we want.'

He paints a picture of cities that connect to people locally, to each other and out on the global stage. ‘Place to place connectivity is really import,' he says. ‘Government needs to recognise that London, Bristol, Cardiff, Liverpool are playing a role in keeping the UK connected to the world.

‘We have phenomenal global connectivity through our people. We need to begin to make use of that feature of cities and recognise it as a national asset, an untapped opportunity.'

‘There is a web of connectivity between cities. It is really worth exploring that.'