Economy Minister Simon Hamilton has produced amending legislation which would reduce tariffs paid to about 1,800 people who got into the scheme before November 2015.
The legislation has not been yet been approved by the Department of Finance.
It is understood that departmental officials will continue to assess the plan over the weekend.
The RHI scheme was set up by former first minister Arlene Foster in 2012 when she was enterprise minister.
Its aim was to increase consumption of heat from renewable sources.
However, businesses received more in subsidies than they paid for fuel, and the scheme became heavily oversubscribed.
It could lead to an overspend of £490m over the next 20 years.
Mr Hamilton's plan requires an assembly vote to change the tariffs from the new financial year starting in April.
It also proposes a public consultation on a longer-term solution.
But there remains an acceptance within the Department for the Economy that any moves on tariffs could face a legal challenge.
Earlier this week, Mr Hamilton formally submitted the plan to the Department of Finance for approval.
At that time the Finance Minister Máirtín Ó Muilleoir said he had tasked "my top economists, legal advisors and accountants to conduct a thorough and professional assessment of the proposals before reporting back to me with their recommendations".
"I have told them that they should apply themselves expeditiously to the task at hand. The operation of RHI has been botched, the solution must not be botched."
On Monday, MLAs are also due to vote on legislation which will mitigate the impact of the so-called bedroom tax.
The "bedroom tax" is a Westminster government policy which cuts housing benefits for some social housing tenants.
A plan to cut costs associated with the Renewable Heat Incentive (RHI) scheme could be approved by MLAs on Monday.