A parliament that doesn't have control of its own elections is not a proper parliament. But that's not the most obvious reason why Holyrood should be given power over electoral law. It should be unthinkable, after what happened last time, for the Scotland Office to remain in charge of future Holyrood elections. It would be like handing Heathrow Terminal 5 back to the BA baggage handlers.

Moreover, giving Holyrood power over elections may be the only way of ensuring that a repeat of last year's election-night chaos doesn't cause a serious breakdown in relations between the Scottish parliament and Westminster. The present divided responsibility exacerbates electoral tension and invites Holyrood politicians to blame London for anything that goes wrong. This is not the way to introduce stability to the constitutional settlement.

I can't understand why the MPs on the Scottish Affairs Committee, who yesterday ruled out any transfer of authority, can't see this. There are few propositions in politics more glaringly obvious than that elections should be in the charge of the legislature that calls them. Westminster obstructionism merely hands the propaganda advantage to Alex Salmond, who can say that MPs care more about maintaining control than about making Scottish democracy work.

This isn't some nationalist plot to gerrymander Holyrood elections. The official Gould Report into the election-night chaos in May 2007 called for Holyrood to take control of its own elections, saying it was the "logical" alternative to the fragmented status quo.

The Scottish parliament has voted for the Gould report to be implemented, and most of the Scottish media believe legislative transfer is inevitable. Even the News of the World is in favour. But Westminster has said no, without even bothering to give any arguments to back its decision. Astonishing.

The Scottish Select Committee's report, published yesterday, is damning about the Scotland Office's handling of the Holyrood election "disaster", in which some 140,000 voters were effectively disenfranchised. It is even more scathing about the Electoral Commission's being asleep at the wheel. "It is difficult," says the report, "to see the Electoral Commission as having added any value to this entire process". In other words, it is a waste of space. Following the Electoral Commission's inept handling of the Holyrood campaign donations row, it must surely be only a matter of time before this dysfunctional watchdog goes the way of the Child Support Agency.

While apportioning blame for the election fiasco, the MPs fail to draw the obvious conclusion that responsibility for the conduct of elections should be transferred to where it matters, saying only that there should be "organisational changes on the ground". Transferring legislative authority is "not necessary", according to MPs. It is understood that the Scottish Secretary, Des Browne, endorses this view strongly and that there is no prospect of legislative transfer before the October deadline.

But it is no accident that the May vote was a mess. As the Gould Report made clear last year: "The fragmented roles and responsibilities for planning, organising and conducting the polls hindered the ability to achieve problem-free elections at every stage." Or, put another way, the bodies involved were tripping over each other while refusing to take responsibility for what was clearly an electoral train-wreck in the making. Effective management needs one boss, yet elections in Scotland are split three ways between Holyrood, the UK government and Scottish local authorities.

Ultimate responsibility lies with the Scottish Secretary, but ministers with multiple briefs, such as Des Browne, have better things to do than get involved in the minutiae of electoral administration in provincial legislatures. His mind is quite rightly preoccupied by the wars in Afghanistan and Iraq, and the humanitarian disaster in Burma - not the efficiency of e-counting in Holyrood constituencies. The minister who actually had responsibility for the botched ballot papers and the election timing in 2007 was Mr Browne's predecessor, Douglas Alexander, a young minister on his way up, whose thoughts were clearly on his next job.

But what the Scottish Select Committee failed to stress - curiously - was the responsibility that Holyrood shared for its own polling fiasco. The double reverse ballot paper, which confused so many Scottish voters, was actually the result of an electoral fix by the big parties, designed to minimise the vote of the little parties. Labour wanted to stop its supporters splitting their tickets by voting Labour in the first constituency ballot and then voting for another party, red or green, from the second "top-up" list. The wheeze was to reverse the order of voting and put the regional vote first on a combined ballot paper, in the hope that this would encourage the elector to vote straight Labour.

But the SNP saw this coming and added their own fix, replacing the traditional party designation with a slogan: "Alex Salmond for First Minister". Coming at the head of the new, improved ballot paper, this gave the SNP an eye-catching advantage, which may have earned it a lot of votes. Labour accepted this dodgy designation as a quid pro quo for its own jiggery pokery. Both parties were guilty of playing fast and loose with democracy. This was what Ron Gould meant when he said that voters were "treated as an afterthought" and that "partisan interests" dominated the electoral reforms.

Now, you might be wondering, if Holyrood was equally to blame, why MSPs should be given responsibility over elections. But responsibility is precisely the point. MSPs played their games because they didn't really have to answer for their actions - they could always just blame Westminster. Holyrood must be put in charge so that the voters know who to blame next time, and to prevent Scottish politicians off-loading responsibility.

There are arguments against giving Holyrood authority over elections, but they aren't ones that stand up to the light of day - which is probably why MPs didn't consider them. They reduce to an incoherent fear the worry that the Nationalists might be able, in some obscure way, to manipulate the electoral system to their own advantage. There may also be a suspicion that Alex Salmond might be able to call a referendum on independence, though I can't see why, since responsibility for the constitution remains with Westminster.

It's not too late for the Scottish Secretary to change his mind. He could open a debate on the matter over the summer, and then make a dignified retreat before parliament returns. There are some battles that it is better to lose. It is bad enough for the Scottish Parliament to be told that it isn't fit to manage its own elections; but it is arrogance of Robert Mugabe proportions for the Scotland Office to cling on to a responsibility it is so manifestly ill-equipped to discharge.