John Swinney says SNP facing its biggest challenge for years

The SNP leader, John Swinney, speaking at the launch of the party’s general election campaign in Glasgow. Photograph: Jeff J Mitchell/Getty Images

John Swinney has described July’s general election as “the biggest challenge the SNP has had for years” as he used his party’s official campaign launch to repeatedly attack Labour, which is threatening the nationalists in dozens of seats across Scotland.

Swinney, who told the rally of more than 200 activists and former MPs in Glasgow that it was a “surprise” to be leading the SNP into an election campaign, added that “voters are right to remind us never to take anything for granted”.