UK Labour leader Jeremy Corbyn has pledged to end the so-called rape clause for child tax credits if he becomes Prime Minister next month.

Under welfare changes brought in by the UK Government, payments are limited to a maximum of two children unless the third or subsequent child was conceived through rape.

The mother of the child has to fill out a Department for Work and Pensions (DWP) welfare exemption form to apply for the additional funding.

The party's manifesto will state: "The cuts to work allowances in Universal Credit (UC) and the decision to limit tax credit and UC payments to the first two children in a family are an attack on low-income families and will increase child poverty.

"Labour will reform and redesign UC, ending six-week delays in payment and the 'rape clause'."

Corbyn said: "Labour will end the abhorrent rape clause across the UK.

"Kezia Dugdale's powerful speech in the Scottish Parliament demonstrated the heartbreaking reality of the rape clause.

"Theresa May and Ruth Davidson should be ashamed of this policy. Only a Labour government that works for the many, not the few, can bring this policy to an end."

A Scottish Labour spokesman told STV News if the party forms the next government then rape victims will immediately stop having to fill out a form to get the additional money.

"Long-term, the two-child cap will go as part as an overall reform of tax credits and UC," he said.

Rape victims who claim for the additional funding must be able to provide the DWP with "any available evidence of a conviction for rape", "any available evidence of an award made under the Criminal Injuries Compensation Scheme" or by a third-party professional giving testimony on their behalf "about the non-consensual act or coercive or controlling behaviour you experienced which relates to the conception of your child".

Opposition parties have criticised the policy.

First Minister Nicola Sturgeon labelled the form "immoral" during a debate at the Scottish Parliament and Scottish Liberal Democrat leader Willie Rennie said the policy must be scrapped to "bring compassion back into the welfare state".

The Scottish Conservatives have defended the two-child limit and the form to claim the rape exemption.

The party's leader Ruth Davidson has said however "if there was better ways" found at providing the additional money while keeping the limit then "we should always look at them".