The Green Party said it will not support Labour's financial plan for the city in its current form or the Conservative amendments at Budget Council this evening (February 28).
The Labour administration is attempting to get its budget for 2019/20 approved at Hove Town Hall.
But it will need support from either the Conservatives or Greens to get its budget through.
After a political shake-up last week, Labour now has 19 councillors, but has the support of the newly-formed Independent Group made up of former Labour councillors Warren Morgan and Michael Inkpin-Leissner.
The Conservatives have 21 councillors and the Greens have 11, and both have tabled amendments to Labour's budget.
Related stories: Council tax rise and jobs axed at Brighton and Hove City Council
Referring to the budget vote, and perhaps to next week's vote on which party controls the council, Conservative councillor Steve Bell said: "The ball is being batted from one side of the chamber to the other and the Greens are definitely the net."
In his opening speech, Labour leader Daniel Yates took a swipe at Conservative leader Tony Janio.
Criticising the Conservatives, he said: "I can see what Tory ambition does for local government. I can look East and West of us.
"We aren’t ambitious to deliver library closures and debts piling up like Tory controlled East Sussex
"We aren’t ambitious to deliver drastic cuts to supported housing services and homeless services like Tory controlled West Sussex
"That’s the very real threat of Tony’s tepid Tory ambitions for our city."
Cllr Andrew Wealls, the Conservative finance lead, criticised the Labour committee chairs for their records.
He took aim at Labour for 'petty party-political in-fighting' reading back a quote from former Labour leader Warren Morgan on the Green Party.
He said action on refuse and recycling collection was 'woeful', criticised the administration on its attempt to increase beach hut fees, homelessness and its attempt to cut respite services for young people with disabilities.
But in his last budget speech - as he won't be standing for re-election in May - he called for parties to work together.
Conservative leader Cllr Janio said his party would deliver lower council tax, from 2.99 per cent to 2.6 per cent, 'by reducing only bureaucracy and waste'.
He said: "Conservatives will deliver the services you need while costing you less."
And Cllr Ollie Sykes, the Green finance lead, said: "We not going to support the current budget as presented... Labour has to do better than this. Services are being cut and there is a paucity of political effort or vision in this budget.
"Will also not be supporting Tory amendments. Putting aside the fact that their national party of empire-obsessed disaster capitalists is dragging this country backwards as fast as they can, these amendments are either deeply damaging or unnecessary or both.
"How Tories can rail against a proposed three per cent (Labour) council tax rise while saying not a word about the 14.5 per cent Conservative rise in police precept is a question people might like to put to them."
The budget meeting started at 4.30pm and can be watched live here.