Communities First, a flagship scheme aimed at boosting deprived communities in Wales, is being axed.
Carl Sargeant, the communities secretary, said performance had been mixed and "poverty remains a stubborn and persistent challenge".
The announcement prompted a fiery exchange in the Senedd with Plaid Cymru leader Leanne Wood calling the lack of a replacement scheme "scandalous".
Funding at 70% of the current £30m level will be given until March 2018.
The debate also saw the minister publicly rebuke fellow Labour AM Mike Hedges after he criticised the ending of Communities First.
Mr Sargeant, who had previously said he was minded to scrap Communities First, told assembly members on Tuesday it was being phased out, saying: "No single programme can tackle poverty."
With reduced funding guaranteed until March 2018, the minister said he would establish a legacy fund from April 2018 of £6m to allow councils to continue to maintain "effective interventions or community assets".
But Ms Wood accused Mr Sargeant of "walking away from our poorest communities", saying it was "scandalous" he had not set out a replacement scheme.
She said the minister had accused Plaid of "jeopardising" the programme in the past, and had claimed Communities First "was only safe with Labour".
"Neither of those statements were true, they were pure spin," she said.
In response, Mr Sargeant accused Ms Wood of making a "political swipe".
The announcement also led to a spat between the minister and backbench Labour AM Mike Hedges which led to Mr Sargeant publicly rebuking his party colleague, accusing him of trying to "frighten people".
Mr Hedges listed a series of programmes that he suggested would now end, saying it was a "sad day" for his constituency, Swansea East.
"A sad day for health as smoking cessation, smoke-free homes, exercise classes, healthy diet programmes... end," he said.
"A sad day for people who would have benefited from money awareness courses, utility bills advice, basic budgeting courses and income maximisation programmes."
In response, Mr Sargeant said: "The member is wrong, quite clearly wrong to say all those programmes will end.
"He doesn't know if they'll end, I don't know if they'll end."
He added: "It is rather unfortunate that the member uses that type of language to frighten people as opposed to be constructive in the way he approaches this in the chamber."
740 posts 'funded through programme'
The Welsh Government said most recent figures indicate 740 posts were funded through the Communities First programme.
Over the next year bodies which deliver Communities First "will be looking at opportunities for redeployment for many staff", a spokeswoman said.
"Our phased approach is designed to reduce the impact on staff."
Communities First spends about £30m each year, with more than £300m spent since it was launched in 2001.
At one point it was supporting about 200 projects, before the number was reduced amid worries about its effectiveness.
In 2011, the head of a Communities First project in Wrexham was jailed for fraud after she diverted funds from the charity to herself and her family.
More recently, in 2015, it emerged that one project in Merthyr Tydfil spent most of its £1.5m budget over three years on salaries.
Port Talbot community regeneration charity NSA Afan had its Communities First funding terminated by Welsh Government in January.