The 37-year-old is vying with Monica Lennon to be announced as the new leader to replace Richard Leonard at the helm of the party.
He issued a statement on Monday thanking members after receiving the most votes in the Scottish Labour list selection ballot in the Glasgow region for the coming Scottish election.
But Mr Sarwar also confirmed he would voluntarily step aside from the top spot in Glasgow and be placed second on the list.
The move is linked to a Scottish Labour ambition for 50 per cent of the party’s top list candidates to be women for the May election.
The policy follows the Scottish Executive Committee’s (SEC) support for the STUC union’s ‘Step Aside, Brother’ campaign.
Mr Sarwar said: “We have a really strong Labour team going into this vital election.
“Our SEC encouraged candidates to follow the STUC’s ‘Step Aside, Brother’ campaign to ensure that at least 50 per cent of our top candidates are women, and I want to lead by example so will be stepping aside from the top spot, meaning we can fulfil that ambition,” he said.
“In truth, our party must do more in future to empower and encourage a greater diversity of candidates – in parliaments and council chambers.
“I want to work with our diverse membership to increase representation of women, BAME, disabled, LGBT+ and other minority groups in society.”
The move by Mr Sarwar is likely to place added pressure on Mr Leonard to follow suit for the Central Scotland region.
Mr Leonard was last year accused of going back on his word to boost black and ethnic minority representation in Holyrood.
The Scotsman reported in June how previous actions to ensure BME candidates would be shortlisted had been dropped from the selection process despite a commitment made by Mr Leonard during his campaign to be party leader.
Mr Sarwar issued the statement as a letter sent to Scottish Labour general secretary Drew Smith called on the party to abide by equality law on list selections.
In the letter, Shereen Benjamin, on behalf of Labour Women’s Declaration, said the group was supportive of the aims of the Women 50:50 campaign, which seeks to increase the number of women holding elected office at every level of democracy.
"Women are under-represented in public life in Scotland," the letter states.
"Just 29 per cent of local councillors and 23 per cent of council leaders are women. Only a third of MSPs are women and in the 2016 Holyrood election, fewer women were elected than in 1999. We cannot afford to lose what progress there has been in increasing the number of women in Parliament this May.”
The letter adds: "The process to select candidates for constituencies and regional lists is under way and we ask you for an assurance that you will uphold the law when it comes to deciding who qualifies as a woman for the purposes of positive action measures designed to increase female representation.”