The wrecking ball has been taken to the derelict Brown and Root Tower site as developers finally begin to overhaul the building once voted the ugliest in London.

For decades the despised tower has loomed over Colliers Wood with its open car park attracting crime, drug users and even providing a set for porn movies, according to reports.

But less than a week before a council order demanding site improvements comes into affect, owners Criterion have begun refurbishment work with the first phase – the destruction of the car park.

More than 200 homes will be created in the fully reclad tower as developers react to the council’s ultimatum of either beginning construction or securing the site following reports of loose masonry falling on to the pavement.

Criterion and the council had been in a deadlock since 2008, with the developers appealing for less restrictive planning constraints in the teeth of the recession.

But at a public meeting in February, organised by incumbent Mitcham and Morden MP Siobhain McDonagh, more than 100 residents voiced their anger at the condition of the 17-storey structure – which they claimed was crumbling dangerously and had become home to rough sleepers.

Ms McDonagh said: “It’s a good start that following the public meeting I organised, the council and Criterion have pulled their fingers out , but there’s a long way to go and residents will not relent until the tower is completely refurbished.”

However, Councillor Diane Neil Mills, Merton’s cabinet member for finance and regeneration, claimed the council’s preferred development option was for the tower to be dismantled.

She said: “The building’s not in the council’s ownership and [the developers] have planning permission so they’re entitled to start refurbishing the tower after Labour allowed them to do so in 2005. But if you’re asking what the council would like to see, that’s for it to be taken down.”

With the tower directly above the Northern line it could only be taken down piece by piece – a process developers have always maintained was not financially viable.

Michael Hughes, head of development at Criterion Holdings, said: “We are demolishing the car park and work on the tower will begin within four months.”

Keith Spears, founder of Making Colliers Wood Happy, said: “It really is disgraceful such a landmark building that can be seen from miles around should have become such a symbol of urban squalor and decay.”

A BBC poll saw the tower voted London’s ugliest building in 2006.