Environmentalists and road safety campaigners against plans to increase UK speed limit to 80mph

The UK Government is planning controversial proposals to increase the maximum speed limit from 70mph to 80mph.

Transport Secretary Philip Hammond will formally make the announcement at the Conservative Party conference in Manchester, which starts at the weekend.

Ministers believe the move will be popular with motorists and will boost the economy by making it faster to deliver goods and services.

However, there has already been opposition from environmentalists and road safety campaigners.

The proposal has caused friction between Tory and Lib Dem ministers in the coalition government.

It is understood Climate Change Secretary Chris Hune has argued that the 10mph increase will see cars use more fuel and so increase pollution.

Health Secretary Andrew Lansley is said to oppose the move on the grounds that it could lead to an increase in road casualties.

If implemented, the 80mph maximum speed limit would apply to dual carriageways and motorways in Scotland.

The Scottish Government wants to have the power to vary road speed limited transferred from Westminster to Holyrood under changes being considered to the Scotland Act.