LONDON (Reuters) - Scotland's devolved government is expected to join a legal challenge against the British government's plans to trigger an exit from the European Union, the lead claimant in the court case said on Sunday.

A British court ruled on Thursday that the government needs parliamentary approval to start the process of leaving the European Union, potentially delaying Prime Minister Theresa May's Brexit plans.

The government said it would appeal against the High Court ruling and Britain's Supreme Court is expected to consider the case early next month.

"We are expecting a number of governments to join us," Gina Miller, an investment manager leading the court case against the government, told the BBC. "But their case will be different to ours. They will be talking about their own particular interests."

(Reporting by William James; Editing by Adrian Croft)