Women are being "shafted and short-changed" by a decision to accelerate the rate at which the state pension age is to be equalised, an MP has said.

The state pension age for women was due to rise from 60 to 65 between 2010 and 2020 but the coalition Government decided to speed up the process in 2011.

As a result the state pension age for women is due to go up to 65 in November 2018 and then to 66 by October 2020.

Critics of the accelerated equalisation believe it is unfair on women who were born in the 1950s who have had to rethink their retirement plans on relatively short notice.

Mhairi Black, SNP MP for Paisley and Renfrewshire South, urged the Government to put in place transitional arrangements to help those women affected.

Introducing a backbench business debate on the subject, she said: "The Government has said that the policy decision to increase women's state pension age is designed to remove the inequality between men and women.

"That's a strange definition of equality if whereby I am being shafted and short-changed purely for the fact of when I am born and the fact that I am a woman.

"That's not my definition of equality."

Plans to increase the state pension age for women were initially set out in 1995.

Ms Black said women are not being given enough time to prepare for the fact that they will receive their state pension later than they may have anticipated.

"There has to be better transitional arrangements here," she said.

"The Conservative ethos is to encourage independence and responsible choice but how can that happen if you don't give people the time to make the responsible choices?

"By continuing this policy at such a high speed the Government is knowingly and deliberately placing another burden on women who are already trying to deal with the consequences of an Act passed 21 years ago that they have only found out about now."

The Baby of the House said that equalising the state pension age "makes sense".

However, she took issue with the fact that many women were unaware of even the initial changes which were set out in 1995.

"The problem is nobody knew about this," she said.

"The reality is that less than half of women knew that this would affect them as late as 2008."

Ms Black added: "Women were not notified, it wasn't reported and they weren't given enough time to be able to make the appropriate arrangements."

Meanwhile, the impact of the Coalition's decision to speed up the process means that those women who are affected "had only five years notice to try and remedy life plans that had been in place for years".

Geraint Davies, Labour MP for Swansea West, agreed and said the acceleration means the life plans of the women affected "has been disrupted and destroyed and impoverished".

Tory Julian Knight (Solihull) suggested more older women could work as a way to offset any losses from the pension changes.

He said equalising the pension age was an "overdue acknowledgement" of the role women play in modern society and that it should not be held up by "short-term political battles".

To protests from Labour MPs, Mr Knight said: "What we need to do is encourage older people's involvement in the workforce as well.

"One of the most encouraging things we've seen by this Government is the fact that people are staying in work for longer.

"Equalising the pension age may pose short-term challenges but is an overdue acknowledgement of the role women play in the modern workforce."

He added: "It would be wrong to take serious risks with long-term economic stability in our pension system for the sake of short-term political battles."

Tory former minister Chloe Smith claimed that going back to the 1995 timetable for equalisation would cost £30 billion.

She said a similar sum will be spent this year on housing and the environment (£28 billion), or public order and safety (£34 billion), according to the summer Budget..

Ms Smith said "we cannot go back" but insisted the Government must do more to make affected women aware of the changes.

She said: "My call today is for the Government to communicate considerably better than has been done to date.

"It seems to me we cannot go back.

"Equalisation does have to mean equalisation, you cannot delay forever on it nor duck it, we need to maintain the principles I have set out and communicate better."

But Labour MPs raised the prospect of the Government losing a legal challenge on the issue.

Former frontbencher Caroline Flint said a successful case had been brought in the Dutch courts on similar grounds.

She said: "Two wrongs don't make a right and these women have been wronged time and time again.

"Given that there's been a successful legal action in the Dutch courts, isn't it better that we form some transitional arrangements rather than let anything happen in the law courts with the decision?"

Labour's Emma Lewell-Buck (South Shields) said: "You are spot on.

"It would be very embarrassing for this Government if the women affected by these changes decided to take individual legal action."

Conservative Marcus Fysh (Yeovil) said he felt sympathy for the women affected by the changes and advised younger generations to start saving money as soon as possible.

He said: "I would give some advice to the younger generations who might be listening to this debate.

"I have some experience in the pensions world and the main thing you have to remember when investing for your retirement is that the earlier you get started in saving, the more money you will have at the end.

"And that's because of the power of compound interest, which has a tremendous effect."

Labour's David Anderson (Blaydon) later told Mr Fysh: "I'm sure the women listening to the debate will be really, really glad you feel sympathy for them.

"You might want to think when you're telling people - lecturing them - about saving earlier in their life that a lot of women we've talked about were actually barred from paying into secondary pensions schemes."

Richard Graham, a Conservative member of the Work and Pensions Committee, said no details have been provided by Opposition MPs about how further transitional arrangements would be funded.

The MP for Gloucester said: "I do believe that it is incumbent on all of us as MPs partly to represent the emotional feelings of our constituents, which has been done very well by a number of members today.

"But also to reflect on the reality and the cost and the implications of what is being proposed, and that, I think, does remain an open question."

Labour's Yasmin Qureshi (Bolton South East) criticised the "patronising and ineffective" use of notices in women's magazines and Sunday supplements to inform women of the changes.

She said: "Some of my constituents directly affected by the changes have told me that even now they have not received any communication or formal notification of the changes from the Department for Work and Pensions.

"This is utterly unacceptable given the gravity of these changes.

"Posting notices in women's magazines and Sunday supplements is both patronising and ineffective.

"None of the women I've spoken to are readers of such publications and found out about the changes by word of mouth."

Labour's Marie Rimmer (St Helens South and Whiston) urged the Government to revisit the changes to help women who had been "dealt a severe, unjust blow".

She said: "Looking ahead, 10 years notice will be given for any future changes to the state pension age to cope with the change in circumstances.

"Isn't that an admission that this was really wrong what has happened?"

Meanwhile, Neil Gray, the SNP MP for Airdrie and Shotts, accused the Government of "unashamedly" moving the goalposts at "short notice for hardworking women".

He said: "The Government is betraying women and I am frankly worried that we will see further undue hardship if the Government does not address the inequalities so blatantly evident.

"It would appear that by not transitioning, this is another example of the Government making cuts in pursuit of their budget surplus holy grail without any consideration of the impact."

Andrew Gwynne, the Labour MP for Denton and Reddish, told the House that "it is time that ministers in the Department for Work and Pensions actually got off their backsides and did something to help these women".

Referring to the Women Against State Pension Inequality (WASPI) campaign group, he said: "Wasps can be pests, they can be nuisances.

"They can't easily be bashed away and when you do they get angry and they come back.

"If you really annoy them they sting you and unlike bees they can sting you more than once so let's have some justice for these ladies because it is long overdue."