Ian Blackford says opposition parties have “a sense of responsibility” to work together to stop a no-deal Brexit.
The SNP’s Westminster leader said MPs had to “be honest with the people of the United Kingdom that we face an enormous challenge”.
But he praised his parliamentary colleagues and rivals who “laid our differences at the door” before meeting to discuss a strategy to prevent no deal.
He added: “Woe betide anyone who doesn’t work in a collective fashion.”