Ruth Davidson is the leader of the Scottish Conservative and Unionist Party. She is a Member of the Scottish Parliament for Glasgow.

This weekend’s SNP conference brought forth the least surprising political headline of the year.

Nicola Sturgeon revealed that, if re-elected in May’s Scottish Parliament elections, the Scottish National party – the party which exists to split the UK – will begin a new campaign for independence.

If I’d read that Jeremy Corbyn wants to put up taxes or that Nigel Farage wants the EU debate to be all about Nigel Farage, I couldn’t have been less surprised.

The new campaign, we were informed, will take the form of an “initiative” over the summer when SNP Ministers will take time away from dealing with the problems facing Scotland’s schools, hospitals and our police force to talk about their “beautiful dream”. I expect this will take the form of a “national conversation”, in which blameless Scottish citizens will be pulled away from their summer holidays to talk to Stewart Hosie about the merits of full fiscal autonomy. Every now and then, Alex Salmond will pop up to declare that another referendum is on its way – that it’s inevitable, round the next corner, just you wait. And more forests will die to produce another document which reveals that, if only Westminster wasn’t there, Scotland could have more generous welfare, lower taxes, better weather and a free unicorn in every back garden.

No matter that it is only 18 months since two million Scots voted against the SNP’s independence “dream” in the last referendum; nor that Sturgeon and Salmond promised faithfully it would be a “once in a generation” event; nor, indeed, that – as we learned last week – an independent Scotland would have started life £15 billion in the red. The SNP won’t even let up when they’re laughed at – as happened to Finance Secretary John Swinney on Question Time last week, when he tried to claim that the SNP “respected” the 2014 result. The SNP’s attitude on the independence referendum isn’t dissimilar to the chronic gambler – every loss is just a win deferred and if they double their money on the next roll of the dice, they can cover their losses.

This central fact about the SNP requires opposition parties in Scotland to remain steadfast. For too long, the Nationalists in Scotland have got away with slowly crow-barring ever wider the gaps between those of us who share our lives in the United Kingdom. My unwavering promise on May 5th will be to back Scotland’s stated wish to remain in the UK. I think we can be a constructive opposition where it matters: on tax, the NHS and education, there is much we can offer. Already, on school testing, on the attainment gap, and on reforms the council tax, we have made our presence felt. But on the constitution, the SNP needs to be told that re-winding Scotland back to the division of the referendum campaign simply isn’t on.

We stand ready in the Scottish Conservatives to do that job – because we’re united in our commitment to the UK. I am afraid this is something neither Labour nor the Lib Dems appear able to provide. Both these two parties are trying to win supporters back from the SNP. Both have put this short term tactical aim before the strategic need to back the UK. Sturgeon’s independence declaration at the weekend has only served to expose the folly of that short-termism. Just a few weeks ago, Kezia Dugdale and Willie Rennie both declared they would “take Nicola Sturgeon at her word” that she would take independence off the table. That now appears rather foolish. No doubt both Labour and the Lib Dems will suddenly rediscover their pro-UK uniforms in the final few weeks of the campaign as they realise the extent of their mistake. Having already said they’re happy for their candidates to back independence, I’m afraid it will all look rather phoney.

In a week’s time, Parliament will be dissolved and the campaign begins. My message hasn’t changed and it is simple. We will deliver the strong pro-UK opposition to the SNP that Scotland needs. That will help deliver the better government and stronger country that most Scots want.