TWO Labour city councillors say they will not support moves to cut jobs and services at the authority.
Budget proposals by the ruling Labour administration are due to go before a full council meeting next week.
They feature proposals that could see up to 600 posts being lost over the next 12 months.
The plans also include the closure of libraries, customer service centres and three motor-based youth projects.
The future of two nursery schools, which also include children's centres, are also under review.
Labour leaders have blamed unprecedented reductions in Government funding for the cuts proposals.
But a small group of backbench Labour councillors say they will not be voting to support their own group's budget plans.
It is the first public rebellion by Labour councillors against their own group since a series of rows in the late 1990s which led to some leaving the party to stand as independents.
Backbenchers Gary Wareing and Gill Kennett confirmed their intentions at a public meeting on Tuesday night organised by the city's recently launched Labour Representation Committee.
Cllr Wareing claimed fellow councillors should be resisting cuts being imposed by the Government rather than simply accepting them.
He said: "Labour councillors were not elected to implement cuts like the ones we are seeing now.
"We were elected opposing what Carl Minns and the Liberal Democrats were proposing to cut when they were in power."
He claimed most Labour councillors and MPs shared his views but were unwilling to make a stand.
"Unfortunately, there has been no fight from opposition MPs in Parliament.
"We now have Diana Johnson speaking out about the unfairness of funding cuts in Hull and it's really good that she is raising the issue but the question must be asked: What happens if the Government just ignores it?
"What next?"
He said Tuesday's meeting could be the start of a grassroots citywide campaign against cutbacks and other welfare reforms being introduced in April, including the so-called bedroom tax.
Cllr Kennett, a former social worker, said: "Former colleagues of mine now face losing their jobs. I will not vote for cuts to the services they help deliver."
She said felt compelled to "draw a line in the sand" over the budget proposals being put forward by Labour.
"When I became a councillor last year, it was on an agenda to fight cuts.
"After being elected, I quickly realised the Labour group was full of decent people trying to do their best for the city and for the right reasons.
"However, as the scale of cuts became apparent, that line in the sand was crossed.
"As Labour councillors, we have a duty to fight these cuts, not just roll over and be complicit in what the Government is doing."
A mass lobby of next week's council meeting is being planned.
