“Brave!” was how colleagues responded when the Conservative leader of Warwick district council, Andrew Day, told them he was going to hold a referendum to see if local residents would accept an increase in council tax to pay for a local climate emergency action plan. That’s “brave” as in “foolhardy”.

It is accepted wisdom that residents will never vote for tax rises. The Bedfordshire police commissioner held a referendum in 2016 to see if voters would back higher council tax to pay for 100 extra police officers. He was trounced. A year later Surrey county council, drowning in cuts, thought about proposing a 15% rise to fund social care and children’s services, but backed off. No one else has dared test the legislation brought in by Eric Pickles in 2012 requiring councils to get voter permission for “excessive” council tax rises. Northamptonshire’s 5% increase in 2019-20 (two percentage points above the threshold of “excessive”) escaped a referendum because the government (fearing a defeat) allowed the near-bankrupt county to simply impose the rise.

In Warwick, the proposed 34% increase in its share of residents’ overall council tax bill this April equivalent to £57 a year – or just over a pound a week – on a band D property, well above the 2% threshold allowed for districts. This will raise an extra £3m annually to fund an ambitious plan to make the council carbon-neutral by 2025. That a council – unanimously backed by local councillors of all political stripes – embarked on such a bold money-raising move is a striking sign of the times. Even councils in relatively affluent areas like Warwick say they have, after a decade of cuts, no spare money. Reserves that once might have funded such initiatives are depleted, and there is no government-funded, green new deal–style fund to draw on.

Warwick’s 7 May referendum will be an interesting test of voter attitudes. Some national surveys suggest voters are fed up with cuts and could live with higher taxes. Have the ravages of austerity – not to mention local signs of climate crisis, such as flooding – cut through? Are enough residents prepared to add the cost of two cups of coffee a month to their annual council tax bill for a band D property of around £1,850?

Warwick asks voters to back radical council tax rise for climate action Read more

The smart money says voters won’t. But, in any case, increasing local taxes in a tiny council in one of the top 20% wealthiest areas of the country is not a universally replicable model. It won’t work for large councils in the 20% most deprived areas with higher needs and a much weaker tax base, and they face a climate emergency too.

Local government – as the recent floods have proved – is on the frontline of any state response to major societal challenges, whether climate crisis, an ageing society or public health emergencies like coronavirus. A decade of austerity, and a funding system based largely on outdated local property taxes, have left it with limited capacity to handle them.

Wednesday’s budget may be more of a disaster relief statement than the opening act of a supposedly post-austerity Tory government. It is the autumn spending review that should give us a clearer view of how seriously the Johnson administration takes the crisis in local authority funding – one that, even Tory leaders in local government would agree, needs urgently fixing.

• Patrick Butler is the Guardian’s social policy editor