Cable challenges Osborne on growth as Westminster budget battles break out Business secretary Vince Cable wants assurances on growth. Vince Cable is refusing to accept deep cuts to his departmental budget without a guarantee of billions in funding for job-creating capital projects, as arguments over this week's spending review reached a new pitch. With just three days before George Osborne is due to announce £11.5bn of cuts for 2015-16, the business secretary was said to be in no mood to back down in a dispute he regards as crucial to the government's economic credibility. Cable is arguing, in talks with Treasury ministers and officials, that the coalition must have "a strong story to tell on growth" to run alongside its tough message on slashing the budget deficit and balancing the books by 2018. In a dispute that has pitched him against the Treasury chief secretary Danny Alexander, a fellow Liberal Democrat, Cable is fighting for investment spending on everything from science and business funding to grants for training and skills development. Insiders said that he was not pushing a party point but a case he believed was in "the national economic interest." In March, some raised questions over Cable's future in the cabinet when he broke ranks to ask, in an article in the New Statesman, whether the government "should borrow more, at current very low interest rates, to finance more capital spending: building of schools and colleges; small road and rail projects; more prudential borrowing by councils for housebuilding." Osborne is expected to declare on Wednesday that the economy is moving from "rescue to recovery" and to hold out the prospect of more emphasis on infrastructure spending. Hailing the achievements of the coalition in saving "money on welfare and waste" he will pledge to invest "in the roads and railways, schooling and science our economy needs to succeed in the future." But Cable is said to want specific commitments for his own department on capital spending. Osborne is also expected to announce a cap on welfare spending. Most departments were said to have already settled or to be close to settling their budgets with the Treasury, with cuts in unprotected departments (those other than health, education and international development) averaging about 8.5%. Ed Miliband - determined to blunt Tory charges that Labour remains a party of high borrowing - said he would be "ruthless about our priorities in public spending" if the party won the 2015 general election. "Nobody here should be under any illusions: the next Labour government will have to plan in 2015 for falling departmental spending," he told Labour's national policy forum. Miliband said that his "starting point" for 2015-16 would be that "we won't be able to reverse the cuts in day-to-day, current spending unless it is fully funded from savings elsewhere or extra revenue, not from more borrowing. So when George Osborne stands up next week and announces his cuts in day-to-day spending, we won't be able to promise now to reverse them, because we've got to be absolutely crystal clear about where the money is coming from. We will show the discipline that the challenge of our times demand. It is the only way we can credibly change our country. It's a hard reality. I am clear about it. Ed Balls is clear about it. And everyone in the Labour party should be clear about it too. Miliband's speech will dismay some on the Labour left who say the party should offer an alternative spending plan to the coalition. Former cabinet minister Peter Hain will support a campaign this week by the centre-left pressure group Compass for Labour to abandon austerity as endorsed by Osborne. Compass believes that it would be "politically and economically disastrous" for Labour to follow Osborne's lead and will call for a £55bn stimulus package to create one million jobs. The group says Britain "cannot endure more unnecessary years of austerity and those who are least to blame for the crisis must not pay the price of it." Nick Clegg has said that - with another coalition government increasingly likely after the election - his party would learn from power-sharing with the Tories, and the next Lib Dem manifesto would not promise things that were unrealistic.