As I write, dusk is falling. It is bleak, miserable and 4pm. The idea that because I am Scottish I have some unique gloomy attachment to this unnecessary state of affairs is misguided and now is the time to say so. Our Presbyterian nation, in which spiritual darkness is often bemoaned, should rise up and say: "Let there be light." This Friday, MPs will have the opportunity to do so during the second reading of John Butterfill's British Time (Extra Daylight) Bill.

We all have sympathy with Shetland crofters and it is true that those of them who attend to their agricultural duties in the mornings would spend an hour more of their pre-breakfast time in darkness on (according to the pro-change lobby) 40 days of the year. This is regrettable, though not more so than for their counterparts in northern Sweden, who survive happily on European time.

However, it should be remembered that Lerwick is more distant from the central belt of Scotland than is London. There is, therefore, a balance of consideration within Scotland as elsewhere.

A columnist in the Stornoway Gazette, not exactly a publication of the effete South, recently commented on the heart-rending account which someone in Oban persuasively offered to Today listeners about how he was suffering darkness while people in the South, even without change, were enjoying daylight. The writer found this difficult to understand since he, 100-odd miles farther north, was at that moment watching dawn breaking. Beware the over-egging of the pudding.

Michael Forsyth, the Secretary of State for Scotland, should certainly have done so before jumping in so prematurely to denounce the Butterfill Bill. Apart from his allegiance to the farmers' lobby, Forsyth was presumably motivated by a desire not to be outbid by the Nationalists, for whom any proposal which emanates from Bournemouth must by definition be tainted with anti-Scottish prejudice.

Forsyth's determination not to be left behind in the rush for the bandwagon raised the stakes and could possibly condemn the Bill to an early death. His ability to stop its progress became a litmus test of his own influence and standing. If he fails, ridicule will descend upon him.

It would have been a lot better if Forsyth had taken account of the clear division which exists within Scotland and had done his bit to prevent this becoming an artificial Scotland-v-England encounter.

After Butterfill's intention was declared, I wrote an article in my own local newspaper. If one was to believe some of the more hysterical opponents of change, I should have expected a deluge of hostile letters and demonstrations in support of evening darkness. In fact, I have not had a single critical letter. MPs' mail-bags are much smaller than boasted of, but if an MP has caused offence then he certainly hears about it from his constituents.

Among the Scottish organisations supporting change are the Association of Police Officers (Scotland); the Royal Society for the Prevention of Accidents (Scotland); the Scottish Sports Council; the Scottish Chamber of Commerce, and the National Playing Fields Association of Scotland. Not a bad line-up! Fortunately, some Scottish Labour and Liberal MPs take a more measured view than Forsyth and will be giving the Bill a fair hearing.

My reasons for favouring change are straightforward. First, I respect the evidence that it is likely to lead to fewer accidents, particularly those involving children. This is unprovable one way or another until genuinely comparable figures can be obtained, and we cannot have these without at least an experiment. The Transport Research Laboratory believes the change would be likely to lead to 60 fewer deaths and serious injuries and 270 fewer slight injuries a year on Scottish roads, taking account of travel patterns and the fact that more accidents occur in the afternoon than the morning.

I am wary of such precise hypothetical statistics, but the general point surely cannot be dismissed lightly, as Forsyth has sought to do.

Most of the other arguments cancel themselves out. Yes, I am sympathetic to postmen facing increased risks of attacks through working in the dark. But, equally, I am concerned for women who are vulnerable to attacks as they make their way home from work in the early evening.

All these points can be evaluated only once the change is made. Parliament could then change back again, if it so wished. What is incontrovertible, in Scotland as in the rest of Britain, is that there would be more time all year round for people to enjoy the pleasures of daylight. The ScotNat jibe that this is all to serve the interests of "the South of England leisure industry" is paranoia at its most absurd. Do we not also have a leisure industry in Scotland? And do we not have a population that wants and needs more leisure? Are our noses to be cut off to spite the faces of "the English"?

Forsyth's colleagues in the Cabinet should tell him to hop off and support a genuinely free vote in the House of Commons. If the Bill survives on Friday, I am going to take democracy one stage farther and allow my constituents to influence how I vote by conducting a ballot through my local press. Perhaps if every Scottish MP did the same, the polarised position which the Tories and the Nationalists have decided is expedient would seem even more fallible.

The writer is Labour MP for Cunninghame North.