The government will try to push the Welfare Reform Bill through Parliament by declaring all of the Lords amendments to it null and void under the "financial privilege" enshrined to the Commons, sources have told HuffPost UK on Wednesday night.
The Commons voted to overturn a series of key Lords amendments to Iain Duncan Smith's flagship legislation earlier on Wednesday.
Immediately after those votes senior ministers used a procedural committee to declare the Lords amendments invalid, under archaic conventions which state that the Lords may not rule on financial matters.
This is a crude use of protocol to prevent the Lords from further delaying the Welfare Reform Bill beyond the end of the financial year, with one senior Labour source telling HuffPost UK it went far beyond any tactics used by the Thatcher government.
The Lords have already indicated they will seek legal advice on the government's new approach to pushing the Welfare Reform Bill through. Peers had expected to consider the Commons' overturning of their amendments sometime within the next fortnight, but the brinkmanship by the government on Wednesday evening threatens to remove the Lords from the picture entirely.
The whole process could end up in a judicial review, because it is considered highly unusual for a government to introduce a Bill to Parliament with the intention of it being considered by both Houses, only for it to declare the Bill beyond the auspices of the Lords at this relative late stage in proceedings.
Labour whips believe that Iain Duncan Smith and Chris Grayling want the Bill passed by March the 31st, and the Lords had expected to consider their rejected amendments within a fortnight.
But Wednesday night's revelations suggest the government will seek to bypass the Lords altogether. Whether the Lords behind the seven key amendments to the Bill will be able to mount a cohesive defence against this is unclear.
Parliamentary convention has long stated that the Lords do not deliberate on "money" Bills, such as the Budget. But such legislation is never introduced to the Lords in the first place.
What the government is doing is declaring that the Welfare Reform Bill has financial implications which render the Lords exempt at this crunch stage in proceedings. The most obvious question is why ministers have taken this view now, rather than at the first stages of the Bill months ago.
Labour whips have told HuffPost UK on Wednesday evening that this break with precedent could have further implications for other major government bills going through the Lords, including the legal aid and NHS reform Bills, both of which are highly controversial.
Earlier the Commons voted on party lines to overturn all seven of the key Lords amendments to the Welfare Reform Bill. Iain Duncan Smith offered one concession on the controversial benefits cap for every household, saying there would be a nine-month transition period from the current regime to the new one. Minsters want a cap on benefits for every household of £26,000. The Lords had earlier amended this to exclude child benefit from the calculation. The government overturned that amendment.
On Thursday it will be more clear how the Lords decides to respond to the government's declaration of financial privilege.