LONDON: Britain is aiming to replace short-haul flights with high-speed rail travel in a multi-billion pound plan that is well advanced, the transport minister said Wednesday.

Transport Secretary Andrew Adonis told the Guardian newspaper that plans for a route from London to Britain's second largest city Birmingham would be published by the end of the year.

The route, estimated to cost seven billion pounds (8.2 billion euros, 11.8 billion dollars) could be funded with a public-private partnership.

Under the ambitious plan, a north-south line could be extended to Scotland, while some high-speed trains could be run on existing networks, the newspaper said.

"For reasons of carbon reduction and wider environmental benefits, it is manifestly in the public interest that we systematically replace short-haul aviation with high-speed rail," Adonis said.

"But we would have to have, of course, the high-speed network before we can do it."

Adonis said he would also like to see some short-haul flights between Britain and Europe "progressively replaced" by an ultra-fast rail network.

Prime Minister Gordon Brown's government has pledged to reduce greenhouse gas emissions by 80 percent by 2050.