Can it really be only a year since Johann Lamont resigned as Labour's Scottish leader, describing the party as “branch office” and some Labour MPs as “dinosaurs”? So much seems to have happened since then.

There's Jim Murphy for a start – who was heralded as the saviour of Scottish Labour. Where is he now? Then we had Labour losing all but one of its Scottish seats, including his, in the Tsunami general election. And then Jeremy Corbyn's grass roots revolution and his new strategy of policy by u-turn.

But times have changed in some unexpected ways. Indeed, the Scottish branch office looks in rather better shape right now than the head office. This is because the UK Labour Party has descended into the kind of internecine party warfare that makes the 1980s splits over Bennism look like an amiable disagreement among friends.

This weekend Kezia Dugdale will be the first Scottish leader in many years to be able to claim she leads a more united and stable party than the UK one. The very disarray in UK Labour has opened a space in which the youthful Scottish leader has a chance to remake itself as an unequivocally Scottish party with its own organisation and policy agenda.

“She's the boss,” said Jeremy Corbyn as he put his name to her plan for an autonomous, even federal, Scottish party earlier this week. No, it's not the Independent Labour Party that some have been advocating, building on the ILP tradition of Maxton and Wheatley. But the changes are real on policy making, candidate selection and membership.

We should begin to see a rather different Scottish Labour Party emerge from the wreckage this weekend in Perth. It's bigger for a start, with the Corbyn effect spilling over into increased Scottish membership. The Scottish conference will be allowed to hold a debate on Trident, if the motion is successful in tomorrow's ballot. This is something Mr Corbyn bottled in Brighton last month under pressure from the trades unions.

Ms Dugdale says she is determined to change the Scottish conference into a genuine policy-making forum, with local branches allowed to propose real motions that could even reach the election manifesto. This would be a remarkable development for a party which, under New Labour, practically invented the party conference as empty media event.

And it has real risks. You might get policies you don't want for a start. There may also be serious divisions aired at conference rather than tucked away in policy forums where there is less intense media scrutiny. Indeed, there is a real question now about how the Scottish party relates to Labour's UK National Policy Forum which is supposed to decide policy for the whole party.

There is also a Scottish Policy Forum but this has always been subordinate to the NPF and in the past has merely “fed into” national policy. This may sound rather technical but it is central to Labour as a unitary party. “Subordinate” means exactly that. As Ms Lamont discovered when she wanted to oppose the bedroom tax outright and was blocked by the UK party machinery.

Ms Dugdale is trying to impose a federal structure on a centralist Labour Party. Interestingly, the move is being echoed elsewhere in the party, with Chuka Umunna, the former shadow business secretary, calling this week for a “full scale federalisation” of the UK Labour Party.

Mind you, since Mr Umunna only recently resigned from the shadow cabinet because he couldn't stand the new leader it seems unlikely Mr Corbyn will be praising him in his speech tomorrow, the first major speech the beleaguered Labour leader has given in Scotland.

We can expect George Osborne's defeat on tax credits to figure prominently after Mr Corbyn's successful outing at Prime Minister's Questions. Though SNP spoil-sports will point out that Labour failed to oppose the Tory Welfare Bill as recently as July.

This is the problem. Some Unionist commentators are criticising Ms Dugdale for giving aid to the nationalists by talking about autonomy. Others have said Scottish Labour has no right to be debating things like Trident at all since it is a UK policy reserved to Westminster.

She has already been attacked by party grandees like the senior Labour MP Frank Field for allowing the “Scottish tail to wag the English dog” on issues like the fiscal charter. Ms Dugdale was thought largely responsible for the Shadow Chancellor, John McDonnell’s U-turn on supporting George Osborne's plans for a budget surplus.

But criticism from Labour unionists and the press is exactly what she needs if she is to remake the party as a viable alternative to the SNP. Nothing less will do. Labour had a near death experience in May at the general election and has no choice but to make a decisive break with the UK party.

But without a name change, will the Scottish voters notice? Even if Ms Dugdale does force Labour into adopting a federal structure it needn't necessarily benefit the party at election time. After all, the Liberal Democrats have a federal structure to their party, with separate conferences, and autonomous policy making.

The Scottish LibDems refused, for example, to go along with the UK leadership’s line on tuition fees. But this didn't prevent the Scottish Liberal Democrats losing nearly all their seats in the May general election.

Moreover, we have been here before. Jim Murphy also promised an “autonomous” Scottish Labour Party with “total devolution of policy making”. He even introduced a new Clause 4 to the Labour constitution to that effect and said it was “the biggest change in Scottish Labour's history”.

And of course, Ms Lamont made her own declaration of autonomy when she was elected leader in 2011. Indeed, she said she was now the first true leader of the Labour party in Scotland, rather than just leader of the Labour group in Holyrood.

With all this autonomania, voters might think the party doth protest too much. The central problem is that Labour is a unitary party and always has been uncomfortable with anything that weakens the party's central message. All the UK Labour leadership contenders, Mr Corbyn included, rejected the idea of an independent Scottish party saying it would lead to incoherence.

Which means that when push comes to shove – as it inevitably will – the weight of opinion on the Labour front bench will be to keep control of policy centralised, at least on reserved issues like defence, welfare and the economy.

Ms Dugdale may wish to have an autonomous party, but it will not be able to have a different policy on Trident. Views may be expressed, but the party in the UK will surely insist that it remains committed to a nuclear deterrent.

She has said there will be new “machinery” to resolve conflicts between Scotland and the centre. There is talk of a constitutional convention to reflect the “new politics” of the grassroots Corbynistas.

Scottish voters will be listening hard to Mr Corbyn tomorrow for signs that he recognises – as he hasn't in the past – that Scotland is now another country with different political priorities.

But this is tough and requires real leadership. Mr Corbyn doesn't have a very good track record of sticking to his guns on difficult issues. Federalism could be the next botched U-turn waiting to happen,