The Irish Farmers' Association (IFA) is urging the government to revise TAMS reference costs ahead of the opening of the next tranche.
IFA rural development chair, John Curran said that planning exemptions for slurry storage must also be delivered urgently.
“These two issues in particular have been a bone of contention for farmers for years," Curran said.
"It’s time they were sorted once and for all."
He said that political commitments were made by ministers earlier this year "that both will align with the commencement of the final TAMS tranche of the year".
"That’s this Saturday (September 6). No more excuses," Curran said.
“I’ve no doubt the handbrake has been put on necessary on-farm investment throughout the country as farmers await their delivery.
"Costs have skyrocketed in recent years and have been slow to reduce.
"Department costings, particularly concrete-related ones, are way out of kilter and farmers haven’t been getting the full benefit of the grant rates suggested."
Curran said more funding allocated to TAMS is also needed.
"We can’t have a situation where necessary on-farm investment in animal welfare, nutrient storage, water quality, is constrained simply because the funds aren’t there," he continued.
"That’s exactly what’s on the table if rank and selection comes onto the pitch."
An additional €160 million over the period 2026-2030 will be directed to TAMS and forestry, it was announced recently as part of the revised National Development Plan.
"We have no idea how much of that €160 million will support TAMS investment specifically," Curran said.
"With the level of devastation following Storm Éowyn, particularly along the western seaboard, and the financial supports needed there, you’d have to say more money will be needed anyway.
"On known metrics, we’ve already potentially maxed out twice that already and we are only in year three of the scheme.
"That’s the message we left Minister Paschal Donohoe and Minister Jack Chambers with last week when we met on the IFA pre-budget priorities. We need more funding."
Curran added that the turnaround in TAMS application decisions "appears to have slowed down too".
"We still haven’t cleared fully the tranches that have closed at the start of the year. Farmers can’t simply wait," he stressed.
"There are farms with builders at the ready that can’t commence because they’re waiting on formal department approval. It’s just not good enough.
"I know there are priority procedures in place at a local level for individual cases, but that’s not a sustainable solution either.
"We need to devote necessary resources to clear the backlog and allow works to drive on."
Curran said it is "vital" that TAMS is an "absolute priority" for the government.
"We need adequate budgets and accurate reference costs, and ensure TAMS approvals are expedited to allow works to commence," he concluded.