Richard Leonard said a bid to oust him at a meeting of the party's ruling body is 'entirely factional'.
Senior Labour MP Rachel Reeves pointed to 'pretty dire' poll ratings for Scottish Labour.
Scottish Labour's James Kelly and Mark Griffin both resigned from Richard Leonard's frontbench team.
The pandemic has 'underlined the need for improvement' in adult social care, Nicola Sturgeon said.
Leader Richard Leonard said the Labour Party was a ‘broad church’ and should remain so.
The FM said we shouldn't slip back into 'old and bad ways of doing things' as the economy recovers from Covid-19.
She was challenged by Jackson Carlaw at the final FMQs before the general election.
The SNP, Scottish Tory, Scottish Labour and Scottish Lib Dem leaders clashed on the BBC.
All the Scottish party leaders are out on the campaign trail ahead of Thursday's election.
The debate will be broadcast live on STV at 8pm on Tuesday night.
Nicola Sturgeon, Jackson Carlaw, Richard Leonard and Willie Rennie went head-to-head.