Mr Brown, a former chief whip, is among 85 witnesses listed for the trial, at which Mr Sarwar, MP for Glasgow Govan, is accused of corruption and faces other charges. The trial at the High Court in Edinburgh is expected to last several weeks.
Also on the witness list is the Labour MP Alan Johnson, the former Labour Scottish general secretary Jack McConnell, and a senior Scottish Labour official, Leslie Quinn.
Mr Sarwar, 43, became Britain's first Asian Muslim MP at the 1997 general election.
Mr Sarwar, of Glencairn Gardens, Pollokshields, Glasgow, faces four charges, one with a co-accused, Mumtaz Hussain, 41, of Lesmahagow, Lanarkshire. The charges span a period between January 1997 and May last year.Reuse content