There is no escaping the brutal fact that Scottish Labour was dealt its biggest rejection in living memory at the European elections. We got 9%. Few of us thought there were further depths to plumb after the Westminster, Holyrood and council election results. But we sank further still.

On the key issue of the day, Scottish Labour activists found ourselves saying, “can we talk about something else?”. Talking about inequality and public services is understandable and well-intentioned, but nobody was listening. The electoral effect was to hand a handsome victory to the SNP – a party that has presided over a decade of increasing poverty, ramshackle public services and a stagnating economy. We are deluding ourselves if we do not recognise that as a serious failure.

This was undeniably due to Scottish Labour’s equivocal stance on a second EU referendum. As much was recognised by Richard Leonard, Scottish Labour’s leader, when he signalled following the results that he now supports holding another public vote.

The Scottish Labour Party must now swing fully behind Richard Leonard on this issue. He must be backed by action to support a second referendum by the national party leadership if we are to have a hope of displacing the Tories at the next election, which could come as early as this autumn.

The electoral case is clear. The results last Sunday were bad enough: 9% is a pitiful score for a party that aspires to government. But backing a public vote is crucial to making future gains.

Think of Glasgow North. A target seat, which Labour is within 1,060 votes of taking from the SNP. There, despite a year’s effective campaigning by a strong candidate, only 2,268 people voted Labour at the European elections – yet the Revoke Article 50 petition has 15,127 signatures in that seat.

In Edinburgh, Labour got fewer than 13,000 votes, and came sixth. Over 100,000 people have signed the Revoke Article 50 in Edinburgh. The bald figures speak for themselves.

By equivocating on a public vote, the Scottish Labour Party again consigned itself to electoral irrelevance. Political parties only win when they listen to voters, respond to their concerns (and Brexit clearly concerns Scottish voters), had have the confidence to lead.

Labour MPs in English and Welsh seats are getting mixed messages from their constituents (if maybe not their members) on whether to support a public vote. Of course, the UK leadership must listen to them too. But there is zero value in Scottish Labour sticking to a UK-wide line when we have the power to do things differently. It is strategically blind from a Scottish perspective, as the election results show – and encouraging that Richard has now made this shift.

Richard Leonard’s support for a public vote is the right response. Members across Scotland should welcome it, and back him on this. The Scottish executive committee (SEC) on Friday, the entire MSP group, the unions and the membership should support Richard as he moves the party to where the Scottish people expect us to be: fully committed to a public vote. Hopefully, the next step will be the rest of the party following suit.