Dozens of petitions have been delivered to the UK Government on behalf of women whose retirement plans have been "shattered" by changes to the state pension age.

SNP MPs gathered the petitions on behalf of constituents who are set to be adversely affected by the 2011 Pensions Act.

Some of them will be forced to work 18 months longer than they previously thought before receiving their pension.

The 1995 Pensions Act was designed to bring the state pension for women in line with the age for men over the course of two decades.

The 2011 Pensions Act accelerated that process, however, leaving 2.6 million women born in the 1950s affected by the changes.

The UK Government has previously said the cost of implementing further transitional measures would be prohibitive, estimating a total spend of up to £30bn.

Independent research commissioned by the SNP now suggests alternative proposals to amend the transition period could be implemented for as little as £8bn.

Ian Blackford, the SNP's pensions spokesperson, said he agrees with bringing pension ages into line but attacked the UK Government for breaking its "contract" with millions of women.

He said: "Around 2.6 million women have been unfairly hit by the rapid rises to the state pension age and as a result their retirement plans have been shattered.

"Thousands of signatures have been gathered by local Women Against State Pension Inequality (WASPI) groups up and down the country, which shows the strength of feeling behind this urgent call to the UK Government to provide support for the women affected by these changes."

He added: "No one is arguing against the equalisation of the state pension age. However, these women have paid National Insurance contributions and are due their pension - it is not a benefit but a contract that the UK Government has broken.

"The Tories must do the right thing and listen to the voices of all the WASPI women.

" By using the surplus in the National Insurance Fund for transitional measures the Tories can afford to provide relief and dignity in retirement for millions of women."

The Department for Work and Pensions has maintained a hard line on the issue, with pensions minister Richard Harrington last month saying there are no plans to change the current pensions arrangement.

Mr Harrington said: "I'd like to make it very clear that the government will be making no further changes in this field.

"We've had transition arrangements which cost significantly more than a billion pounds and the longest a person would have to work longer for than they thought is 18 months."

A DWP spokesperson said about the petitions: "The decision to equalise the state pension age between men and women was made over 20 years ago and achieves a long-overdue move towards gender equality.

"There are no plans to change the transitional arrangements already in place.

"Women retiring today can still expect to receive the state pension for 26 years on average - several years longer than men."

The petitions will be presented in the House of Commons chamber before being sent to the UK Government for a formal response.