The coronavirus crisis has exposed Bath and North East Somerset Council's over-reliance on tourism and rental income – and it cannot continue, the authority's finance chief has said.

Opposition leaders have accused the Liberal Democrat administration of a "shocking and irresponsible" failure to plan for the future but councillor Richard Samuel said there was too much uncertainty.

He said he would not develop a recovery plan "built on sand" but the council will have to answer "difficult questions" about which services to cut.

Councillor Paul Myers, who leads the Conservative group, told the full council meeting on July 23: "The response [to calls for longer-term planning] has been that there is too much uncertainty at present time to plan beyond March. I find this attitude shocking and frankly irresponsible as valuable time has been lost and is being lost.

"Given the structural problems we're facing over parking, heritage and commercial estate income, we need a complete rethink.

"It's about time Cllr Samuel actually looked to produce a five-year plan instead of just waiting for the Government to bail us out again and again."

The council initially forecast a £43million hole in its budget.

Earlier this month the Government announced it would compensate a significant portion of the income authorities lose as a result of the lockdown from fees and charges.

B&NES Council is yet to confirm how much it will receive but the funding will not cover the lost £17.5million rental income from its commercial estate.

Councillor Colin Blackburn said complacency is a "recipe for disaster", adding: "We need a long-term vision to understand the potential changes to car parking revenues as we drive climate emergency changes into transport habits.

"We need to consider that millennials don't want to look at old stuff, they want experiences and our heritage might not always appeal.

"We need to understand that as a property holder we cannot guarantee income when the world is changing around us and retail especially is being impacted massively."

He called on the council to draw up a five-year plan but Labour group leader Robin Moss said there was a risk in taking decisions too early.

Lib Dem councillor Winston Duguid questioned how the council could put together a credible longer-term plan when it did not know what Westminster was planning, saying: "The Government hasn't even published their plan for this year, let alone next year or the next three years or the next five years – no plan for raising taxes, no plans for cutting expenditure."

Mr Samuel, the deputy council leader and cabinet member for resources, said: "Opposition councillors clearly don't know me well enough if they think that I would ignore the clear signals about our finances that the current Covid situation has created.

"I have absolutely no intention of letting the council's finances run away with itself.

"There is huge uncertainty about current future Government funding intentions for local government. What I am not going to do is to put a plan to cabinet and then on to council that simply has foundations of sand.

"The council's over-reliance on commercial income from retail property and tourism related activities cannot continue.

"It is not sustainable and that is the cruel reality of the Covid crisis – it has laid bare our exposure to these issues.

"I'd like to know from opposition members – rather than posturing politically about this – which adult social services will they cut, which children's services will they cut, which kind of services that our community's value will they cut. These are the difficult questions we will have to answer.

"We are going to publish a revised medium-term financial strategy in the autumn."