Tri harder to sort out this eyesore – that's the message from protesters who unfurled a banner from the roof of the derelict Tricorn House yesterday.

Another campaigner, masked a bearing a sign saying Power to the People, took to the top of the empty Stroud office block in Cainscross as other protesters held a picnic on the grass below.

The group want the site bulldozed and replaced with new offices, housing and community facilities.

Bearing donuts and flasks of tea they gathered to demonstrate their anger at the decision of government minister John Denham who ruled against Stroud District Council compulsory purchasing the ugly building.

They wanted to show support for Stroud District Council's attempts to get a compulsory purchase order for the 1970s block.

The council intended to sell Tricorn House to renewable energy company Ecotricity, which had hoped to build new HQ on the site.

But, following a public inquiry in July, Mr Denham ruled the CPO was premature without any planning permission for a redevelopment.

Protesters said they would have supported the Ecotricity plan but were now keen to see a development on the site which included social housing and community facilities.

Cainscross parish councillor Deborah Westgate was at the picnic. She said: "We want this eyesore removed. No-one wants to see this here in another five or 10 years' time."

The building is owned by Millville Ltd but has been empty since 1996 and is now derelict and has been targeted by vandals.

The protesters urged the council to revive its CPO plans.

A letter to Mr Denham was signed at the picnic, inviting him to visit Tricorn House to see it for himself.

Another was penned to council cabinet member for development Coun Barbara Tait offering support for a mixed-use plan for the site which will deliver community benefit.

"The district council, Cainscross Parish Council, community and businesses now have the chance to renew a CPO bid," said Martin Large, member of Stroud Commonwealth.

Dr Molly Scott Cato, a reader in green economics at Cardiff School of Management, who lives locally, said "It is clear the green economy we need to build will be powered by renewable energy but, more than that, it needs to be based on community involvement and ownership."

■ People have got until tomorrow to have their say on Ecotricity's Stroud 5050 campaign.

The company wants to gather evidence to show residents' active commitment, or not, to the supply of 50% of Stroud's energy needs from wind turbines. To vote 'yes' or 'no' online, visit the website www.stroud5050. org.