THE SNP response to the loss of more than a third of its Westminster seats can be described as uncertain at best, with no obvious strategy from the leadership.

At worst it could be called wilfully blind - with some senior figures seemingly believing the political dynamic in Scotland has not palpably changed.

However, for a party which has dominated Scottish political life for a decade, the scale of the losses - coming so soon after one of its greatest triumphs in the tsunami general election of 2015 - was always going to be a bitter pill to swallow.

Tommy Sheppard is the first SNP figure of note to acknowledge that many independence supporters found Jeremy Corbyn's manifesto attractive enough to vote for the UK vision of the party in droves. The stress is deliberately placed on the phrase 'the UK vision of the party', rather than on the vision of the shambling Scottish party which self-harmed by trying to undermine Corbyn.

The loss of six SNP seats to Labour in working class constituencies shows Corbyn is at the gate of Scotland's Holyrood's ruling party. This newspaper was sympathetic to many parts of Corbyn's progressive manifesto. Many independence voters found Corbyn policies more attractive than what was for some a timid and managerial SNP prospectus.

However, the popularity of Corbyn's programme failed to register on the SNP's Richter scale during the campaign. Even now, the SNP appears to be struggling to respond to the rise of a genuinely left-wing alternative, something that is unchartered territory for a party accustomed to facing a limp neo-Blairite Scottish Labour party.

The Sunday Herald remains committed to independence because we believe it offers the best long term hope for progressives in Scotland. However, we have never believed in independence as an existential cause. In order to secure the best progressive outcome for the people of Scotland, the SNP must develop policies which provide a vision equal to Corbyn. Championing independence on its own is not enough.

With Theresa May in disarray, the SNP should be at the forefront of putting forward a progressive alternative - a progressive alliance - to a failed government in Westminster.