"What she's done in the last 24 hours is nothing to do with the interests of Scotland," Nandy said.
Scotland's first minister wants the country to vote on leaving the UK on October 19, 2023.
The first minister is preparing to set out her plans for a second vote.
Exclusive: Labour Could Boycott A 'Wildcat' Scottish Referendum And Launch Anti-Poverty Campaign Instead
SNP bosses are reportedly considering the move if Boris Johnson continues to block indyref2.
The snub came just minutes after the SNP leader launched a fresh drive to hold a second vote.
Nicola Sturgeon says her plans haven't changed, but Scottish nationalist hopes of a fresh vote next year are fading fast.
Everything you need to know after "super Thursday".
First minister warns Boris Johnson not to stand in way of second independence referendum as she closes in on a "record-breaking" fourth term.
Former first minister says the aim is to build "super majority" for Scottish independence.
Glasgow MSP becomes the first Muslim leader of a major political party in the UK.