THE MP who uncovered the rape clause had said it may be too late to stop it after the government moved to make it law without a parliamentary vote.

Alison Thewliss first drew attention the rule after it was included without fanfare in a Budget drawn up by then-Chancellor George Osborne in 2015.

Yesterday she hit out after Theresa May’s government added the clause to existing legislation on Wednesday afternoon.

The move means the controversial tax credits rule will come into effect within a month, unless Thewliss can prevent it using a little-used block that was last deployed successfully in 1979.

She said: “Using such an underhand parliamentary tactic to railroad the rape clause into law is just the final insult this government could possibly dish out.

“Not only did ministers sneak out their shameful consultation response as the eyes of the world were watching Donald Trump’s inauguration, but they’re now trying to put the rape clause on the statute books without a vote or debate, let alone any detailed scrutiny by MPs.

“The government must accept this policy is unworkable as well as immoral. With just days until nurses, doctors and social workers are expected to verify whether women had their third child as the result of rape, it’s clear there’s been no sexual violence training for those working with such vulnerable women.

“This is frankly astonishing, especially when you consider that the government is trying to railroad this through using medieval parliamentary procedures.

“This fight isn’t over yet. I’ll do everything in my power to ensure parliament gets its say on this cruel policy.”

Women’s rights groups, domestic violence charities and campaigners were appalled when the rape clause was revealed.

While parents will no longer receive tax credits for more than two children, the rule provides an exemption for rape victims – so long as they can prove the child was conceived through assault.

However, uncertainty remains about how eligible women can seek the necessary consultation with a “professional third party”, exactly what they will have to do, and what protections will be offered.

The government says all changes will be “delivered in the most compassionate way”.

Responding to Thewliss’s comments, a government spokesman said: “It’s absolutely right that we have the right exemptions in place and we have thought carefully about how we will work with charities and health and social care professionals to support victims of rape.

“We will be publishing guidance shortly.”

Thewliss has tabled a motion of prayer for annulment in a bid to block the rule, and has cross-party support.