IN her statement to the House of Commons on last week’s European Council summit, Theresa May said the Brexit bill would be a “defining moment for our whole country”. You can say that again. With Nicola Sturgeon heading to Holyrood to seek approval for a second referendum on independence based on Scotland voting to remain in the EU and Theresa May seemingly intent on a hard Brexit, the UK now faces two incompatible forces heading for an inevitable collision. There can only be one winner.

In this early stage of the campaign, most commentators agree Ms Sturgeon scored the first win by announcing, ahead of Mrs May’s statement on Brexit, her intention to seek a referendum. The First Minister looked bold, with Mrs May left looking like she had been caught off guard. The first point has gone to Nicola Sturgeon.

But has the First Minister made the right choice in pressing for a referendum some time between Autumn 2018 and spring 2019? She may have been influenced by recent polls, including one for this newspaper, which appeared to show the balance of opinion on independence narrowing and made the calculation that in 18 months or so, she could cross the winning line. The most recent Scottish Social Attitudes report also records the highest ever support for independence at 46 per cent, which represents an extraordinary change in just five years – in 2012, it was recorded at 23 per cent.

However, a number of factors will still make the referendum tricky for the SNP to win. Certainly, the polls appear to be heading in the right direction for the party, although the result of the EU referendum has not led to the dramatic swing that many expected. An increase in Euro scepticism detected by the Scottish Social Attitudes survey also complicates matters – could soft Yes voters be inclined to vote No if there is an independence campaign that emphasises support for the EU and immigration? There is also the possibility identified by Professor John Curtice that the demographics are heading in the SNP’s direction, but that the country is not there yet – in other words, Ms Sturgeon has called it too soon.

The question of timing is also far from clear. Everyone agrees the idea of the UK Government saying a flat no to a referendum is out of the question, but that leaves the option of insisting the vote is held after a Brexit deal in 2019. This appears to be the option the UK Government is manoeuvring towards, with the Scottish Secretary David Mundell telling The Herald people could not take a reasoned view on Brexit in the time suggested by Ms Sturgeon.

The First Minister herself appears to have acknowledged this post-Brexit referendum might be an option – her Bute House speech included a line about Scotland indicating it wanted a different relationship before Brexit “or at least within a short time after it”. It is also hard to see how voters could be expected to make a decision before they know what the outcome of the Brexit negotiations is.

There will be many who disagree with that. But even at this early stage it is worth noting, hopefully, the Church of Scotland’s reaction to the debate so far: it is only just getting underway, but there is nothing inevitable about it being divisive and acrimonious.