The man in charge of Southampton City Council has been forced to defend plans to spend £500,000 of a Government windfall.

The huge lump sum has been earmarked for the council leader’s “Getting Our Economy Moving” fund for Councillor Richard Williams to support creative industries, energy-saving initiatives, apprenticeships and internships.

It comes after the Labour-run authority learned it was receiving £5.8m in a one-off Westminster windfall and set about deciding how the money should be spent.

Tory opponents have called for a full explanation of the proposed leader’s fund, which comes as the council bids to slash £20m from its budget in the city’s worst cuts ever.

The Conservative group’s finance spokesman Cllr John Hannides said: “I think all the groups seeing increases in charges will want to make sure that every penny is spent wisely and for the benefit of everyone in the city. They have got reason to expect an explanation as to how this money is going to be used.

“I think any amount of money does require clear explanation as to its intended use – especially at this time when we are seeing reductions in services that people rely on.”

Last night Cllr Williams said a large proportion of the £500,000 would be spent on bringing forward a scheme with energy companies.

Called the Energy Company Obligation, it is designed to dramatically cut fuel bills for homes and create local jobs in fitting better insulation and solar panels. He said: “It is one of our priorities to get the economy moving and the green industry is one of the few areas that are growing.”

As reported, the council also wants to use part of the £5.8m windfall to reduce controversial cuts to library hours. Funding will also be put back into some youth services until they can run independently.

The authority has also come under fire for setting aside £40,000 to keep the mayor’s chauffeured car.

Meanwhile, £500,000 has been earmarked as a safeguard in case the council’s annual Government handout is worse next year.

A “transition fund” of £1m has also been set aside for major changes to children’s social services and reducing the number of city youngsters ending up in care.