PLANS to extend the Edinburgh tram route to Leith and Newhaven have been approved by councillors.

Members of Edinburgh City Council voted "in principle" 44 to 11 in favour of adding the three-mile extension, which is expected to cost taxpayers around £145 million and take until 2021 to be completed.

The current route runs from Edinburgh Airport to York Place in the city centre, but the added section would allow passengers to travel on from York Place to Leith Walk and Newhaven in the north of the city.

Councillors were told that the new development would act as an "economic stimulus" for the capital's waterfront, but that they must "drive a hard bargain" with utility companies who were partly blamed for driving up the costs of the previous trams project.

The line finally opened to passengers in May 2014, five years behind schedule.

Lord Hardie has now been tasked with overseeing an inquiry into why the controversial development was delivered late and £375m over budget.

Council Leader, Councillor Andrew Burns, said: “I am pleased we have been able to find a way forward for the project, which would deliver a range of key benefits in terms of economic growth, greater accessibility and the environment for Leith and the city as a whole.

“It is now our intention to ensure complete clarity before taking the next step, taking into account the needs of the city’s taxpayers.”

However, Conservative councillor Cameron Rose said the extension would prove "ruinously expensive", take too long to complete, and accused the ruling Labour-SNP coalition of "putting the cart before the horse" since Lord Hardie's inquiry had not even begun.

He added: "It is incredible that after the debacle and shambles of the previous trams project, this council wants to press ahead with another before we even have the results of the inquiry."

A nine-month period of site investigation, procurement and other preparatory work will be undertaken, after which a report will be submitted to the council recommending how best to proceed with the development.

The previous trams project was dogged with contractual disputes and controversy which saw construction temporarily grind to a halt.

The council will also reconvene on December 10 when they will consider legal advice on the expansion, including the potential purchase of 67 privately-owned plots of land between Roseburn and Granton which would leave the door open to an additional expansion of the route in future. The council has until May 2016 to exercise compulsory purchase orders to buy the land.

Meanwhile, plans to use cash from taxpayer-owned Lothian Buses to part-fund the Newhaven extension have been put on hold until the council is satisfied there will be no adverse impact on bus modernisation or fares.

The council wants to use at least £25m worth of profits from the bus company, whose parent company, Transport for Edinburgh, also runs the tram network, to help bankroll the initial phase of the tram extension.

It comes after the latest passenger figures showed that 1.55 million people used the trams between May 31 and September 4, 50,000 more than the same period in 2014.

The week ending August 15 was also the service's busiest to date, with 137,000 passengers.

Higher than expected passenger numbers during the first seven months of operation also meant that the public subsidy was £449,000, instead of an anticipated £600,000.