London's River Thames garden bridge backed by Westminster Council

Plans to build a garden bridge across the River Thames are a step closer after Westminster City Council approved planning permission.

The £175m footbridge would link Temple with the Southbank, but has been criticised over its location and cost.

Already approved by Lambeth Council, it is the idea of actress Joanna Lumley and has been designed by London 2012 cauldron creator, Thomas Heatherwick.

The Mayor of London will make the final decision.

The plan includes 270 new trees

Westminster councillors voted 3-1 in favour of the bridge which will cost £3.5m in annual maintenance.

At a planning meeting concerns were raised about the potential loss of views, with heritage groups worried the sight of St Paul's Cathedral will be lost for some.

Civil engineers have also called it "the most expensive footbridge in the world".

Bridge expert Simon Bourne says the copper cladding makes the bridge five to 10 times more expensive than it should be

Bridge consultant Simon Bourne told BBC London the cost is "five to 10 times more than you'd expect a footbridge to be".

He said that is because of its copper cladding.

He said: "One has to view this bridge to a certain extent not as a piece of infrastructure, but as a piece of art. It's not value for money and I don't think it's good design."

But Lord Mervyn Davies, chairman of the Garden Bridge Trust, said: "I think it's a reasonable cost for what is going to be an iconic bridge and I think the cladding is important because it needs to be visually beautiful.

"It needs to be able to stand the test of time."

Robert Davis, deputy leader of Westminster Council, chaired the planning committee and said: "This is something that is iconic and absolutely unique, and will be recognised right across the world.

"I understand the concerns about potential loss of views, but there is no doubting that this bridge will bring substantial and significant benefits to London."

Transport for London has agreed to pay £30m in enabling costs to be matched by the Treasury.

The Garden Bridge Trust says it has raised about £120m which will go towards running costs as well.

As the bridge is a major infrastructure project, the Mayor of London will have the option to call it in for further scrutiny, or allow the bridge to go ahead as set out in the applications that were put before Lambeth and Westminster councils.