See map of proposed routes

Edinburgh City Council confirmed that there was not enough money to build the sections from the airport to Newbridge and from Granton along the seafront.

However if phase one plans are approved, a route from Edinburgh Airport to Leith, via Princes Street, could be up and running by 2010.

Environmentalists hit out at the delay saying trams can helped cut pollution.

Funding gap

Edinburgh City Council published formal plans for the first phase of the tram network on Friday, with the full council debating the issue next Thursday.

The council has set aside �45m out of its capital budget for the scheme, with the Scottish Executive expected to commit to providing �375m.

That figure should be indexed to inflation meaning �490m would be given.

However the �535m that would be available still falls significantly short of the estimated �715m needed to deliver the full two-line scheme.

The funding gap could only be plugged by delving into council tax revenue, something the council has said it would not do.

The postponement of yet another of the tram routes is terrible news for all those hoping to see a safer, cleaner and congestion-free capital Duncan McLaren FoE Scotland

Andrew Burns, the council's executive member for transport, said the whole scheme was still subject to parliamentary approval.

Speaking to BBC Radio's Good Morning Scotland programme, he added: "Once the council and the executive funding is confirmed, we will be able to absolutely guarantee the construction of the section from Edinburgh Airport to Leith waterfront via Haymarket and Princes Street by 2010.

"What we cannot guarantee to be build immediately is the section from the airport to Newbridge and the section from Granton Square out east to Leith.

"The section along the Roseburn corridor from Haymarket north to Granton Square could be built under the sum of money mentioned as long as we keep costs under control."

Edinburgh's Liberal Democrat councillors have welcomed the council administration's decision, saying the only credible tram route for Edinburgh is the one from the airport to Leith.

'Unnecessary link'

However, sustainable transport campaigners TRANSform Scotland said the council had ditched the wrong scheme.

Chairman David Spaven said: "They should instead have taken the decision to scrap the costly and unnecessary Edinburgh Airport rail link.

"We are now left with proposals for two new rail lines to Edinburgh Airport, and no new public transport for Edinburgh waterfront."

Environmental campaigners said they were disappointed with the scheme's delay and blamed the Scottish Executive rather than the council.

"The postponement of yet another of the tram routes is terrible news for all those hoping to see a safer, cleaner and congestion-free capital," Friends of the Earth Scotland's chief executive, Duncan McLaren, said.

"We are angry that, despite their increasing cost, the Scottish Executive can always find enough money to bulldoze through every destructive road building project it wants.

"Yet, when sensible and sustainable transport alternatives are proposed, never enough money is forthcoming to deliver them."

The Scottish Greens said that the tram route not arriving at Granton would undermine the waterfront redevelopment scheme.

Green MSP Mark Ballard said "It is essential that any new development on the periphery of Edinburgh has good public transport links.

"If the waterfront development goes ahead there will be 45,000 new residents in this area of Edinburgh.

"We must have a fast and effective public transport system to avoid massive traffic congestion in the area."