The former Treasury minister sent out to defend George Osborne's 2012 'omnishambles' budget has backed 'honourable' former welfare secretary Iain Duncan-Smith over his decision to resign.

Chloe Smith said she would be calling for the better off to stand on their own two feet urging the government to abandon planned cuts to Personal Independence Payments (PIPs) and look for savings from better-off pensioners receiving free television licences, winter fuel allowances and bus passes.

It comes as the beleaguered Chancellor was forced to abandon £4bn of benefit cuts for the disabled and in the wake of the dramatic resignation of Work and Pensions Secretary Iain Duncan Smith on Friday night in which he said the cuts were defensible in narrow terms of deficit reduction, but not 'in the way they were placed in a budget that benefits higher earning taxpayers'.

The prime minister's official spokeswoman said the government would now bring forward alternative proposals to the cuts to Personal Independence Payments (PIPs) - announced by Mr Osborne in the Budget on Wednesday - in the Autumn Statement towards the end of the year.

But Ms Smith, who as a junior minister in 2012 was sent out to defend a fuel duty u-turn on the late night BBC politics show Newsnight in a famously bruising encounter with former presenter Jeremy Paxman, said: 'I don't think it [personal independence payments] was the right measure to include in the budget, that is what I will be saying in my speech tomorrow.

'Ultimately the Chancellor is responsible for the budget. The Treasury is responsible for trying to collect together all the savings on expenditure. I think it is sensible we are debating the balance of the savings and expenditure. I don't think this is a good proposal and I will be speaking out against it.

'It is a long running piece of work and it needs considerably more attention than it has been given,' she said.

Questioned on whether Mr Duncan-Smith was right to resign, she said: 'I think he is an honourable man who has therefore had to make a decision about what was in his area of responsibility. As elected politicians in a democracy we all have to be confident that we have to justify what we are proposing to do with taxpayer's money. For myself, I will be speaking up for constituents in the budget this week.' She said that the 'main challenge' was what could be saved instead.

'I will be saying in the Commons instead we should be looking at universal benefits, in particular that we give well-off pensioners - a bus pass, a free TV licence and help with winter fuel - when they don't need it. I think that is where we should look instead of this proposal on PIP. 'The budget has to be balanced so we have to look elsewhere for those savings and I think it is important to be constructive about that. 'You have to be able to ask those who are better off to stand on their own two feet.'

Ms Smith, who joined parliament in 2009, was made economic secretary in 2011, but was moved to the cabinet office in a September 2012 reshuffle. She decided to return to the backbenches ahead of the general election in 2013.

'Budgets are a very good example of where you have to get the detail right and the bigger picture right. You are running a county and that is a serious endeavour. 'But you also have to be able to stand back and look at the bigger picture and balance the books and be confident that you are both delivering the promises you made, whilst being as fair as possible. 'The manifesto I stood on made clear we would spend less on welfare, but do so by protecting the most vulnerable.'

She said she had been making representations about welfare changes on behalf of constituents about the detail of aids and appliances within personal independence payments ahead of last week's budget.