Spring forward, fall back – and get ready for SDST

After more than 100 years of debate, Westminster's three largest political parties are close to agreeing that an extra hour of daylight should be added to the long summer evenings.

Labour is believed to be on the verge of endorsing plans to put clocks two hours ahead of Greenwich Mean Time (GMT) during the summer instead of the present one hour. The Conservatives pledged support two weeks ago and the Liberal Democrats said yesterday that they also back the idea.

Under the proposed Single Double Summer Time (SDST) system, Britain would also abandon its alignment to GMT during the winter. From the end of October to the end of March the country would remain one hour ahead of GMT, the same as today's British Summer Time. Such a move would, proponents claim, cut road deaths and slash carbon dioxide emissions because less fuel is burned keeping lights on.

Labour and Conservative frontbenchers have recognised in recent statements the advantages of changing the British time zone. Gordon Brown delighted campaigners last month when he revealed he was "thinking carefully" about making a commitment to SDST. Ben Bradshaw, the Culture Secretary, described it over the weekend as "good for business, good for tourism, good for the environment," and added: "It is high time we moved on it."

And Tobias Ellwood, the tourism spokesman for the Conservatives, said the arguments for a change were "more powerful than ever". Earlier this month he invited all the main political parties to hold talks aimed at reaching cross-party agreement on the issue. The biggest hurdle to change remains Scotland, where there is longstanding resistance to being an hour ahead of GMT during the winter because of the darker mornings, which would affect children travelling to school, and farmers.

The Conservatives want consensus on the changes rather than to impose them. A Liberal Democrat spokesman said: "There are obvious advantages but any change to the system would have to take into account the different circumstances in Scotland."