The UK Government has been warned it will be taken to court if it doesn't put the terms and conditions of the £1billion DUP/Tory deal before parliament.
Gina Miller, the business woman who took the government to court to ensure there was a vote in the House of Commons on the triggering of Article 50 to signal the beginning of the process to leave the EU is now challenging the deal the Conservatives made with the DUP.
After her majority was eroded in last year's General Election, Theresa May turned to the DUP. They brokered a confidence and supply deal.
A £1bn funding package for infrastructure, health, education and other public projects was agreed. In November £50m of the money was allocated.
It is not about the payment, it is about the way you are doing this.
Ms Miller argues the money should only have been allocated with the backing of parliament.
Speaking on Peston on Sunday on ITV she said the government had, in a letter, assured her parliament approval would be needed for the money to be spent.
"And yet we have found out there have been two payments and the government are now saying thy will ask parliament to retrospectively approval it.
"It has not gone through the proper channels and constitutionally they have not got the powers to do this. So I am challenging.
"It is not about the payment, it is about the way you are doing this.
"Time and time again there are examples of government trying to by-pass parliament. The Executive is trying to change the power between itself and parliament."
Ms Miller said a second letter had been send to government seeking assurances the rest of the cash from the deal would be put before parliament for scrutiny. She said she expected an answer this coming week.
"If they come back and say we have done this and if they can not give the assurance we are asking for that there will be a full vote in parliament for the rest of the money, then we will ask for a judicial review."