First minister of Scotland John Swinney warned the public could become disenfranchised with the crisis surrounding postal votes.
The SNP leader praised a “vibrant” election campaign in Scotland, and said he was not taking any regions for granted.
Mr Swinney was serenaded by folk singer Iona Fyfe and posed with a yellow Alfa Romeo Spider convertible at a rally in Glasgow’s West End – although the 24-year-old petrol car does not comply with Glasgow’s LEZ, brought in by the SNP.
He pledged to push back against a Labour government, in particular regarding the two-child limit.
Mr Swinney said he had warned of the risks of holding the General Election in the Scottish school holidays and said he had been “inundated” with concerns from the public.
He later wore a pink cowboy hat as he posed with campaigners.
Mr Swinney told supporters: “Keir Starmer will be the next Prime Minister of the United Kingdom but there’s still one part of the country which still has a vibrant election campaign – that’s here in Scotland.
“We need to make sure we elect SNP MPs in Westminster. A Labour Prime Minister will be carrying on a Tory agenda of austerity and the two-child limit – we have got to have SNP MPs in Westminster.
“What we know is that when decisions are made in Scotland, for Scotland, they are the best decisions.”
Asked about the possibility that Dundee could be targeted by Reform, Mr Swinney said: “I have never gone into polling thinking I can take the day off.
“Even when we’ve been miles ahead I’ve gone in saying ‘I’m not judging this.’”
Mr Swinney praised efforts by the City of Edinburgh Council to ensure people who had not received postal ballots were still able to vote and said he expected an inquiry to be carried out.
He said: “There are steps that can be taken by local authorities to make facilities available so people can vote – I very much welcome what the City of Edinburgh Council did yesterday, other local authorities are considering that as well.
“I’ve asked the election management board to address the fact that some local authorities have done that but others have not done so.
“I’m inundated in my inbox. I suspect there’ll be effects on all political parties.
“But I think the crucial point is the disenfranchisement of individuals.”
He said that the voter ID requirement brought in by the UK Government was “designed to put people off” and more effort should be made to encourage people to vote.
Mr Swinney said: “What the UK Government’s decided to do, we will not be doing that in Scotland.
“We should be maximising the participation of people in elections, not making it more tricky.”