Tories must 'reverse socialist coup' by cutting taxes, Liam Fox warns The former defence secretary added: "I believe that the country will be at its best when the Government is small and people are left to enjoy the fruits of their own labour. Whichever is the case, it is creating a society that is sustainable for the future in a way that our current welfare-dependent and debt-ridden economy is not. Dr Fox's intervention comes amid growing speculation about senior Tories lining themselves up to replace Mr Cameron as Prime Minister. Theresa May, the Home Secretary, appeared to use a speech at the weekend to position herself for a future leadership run. Dr Fox also used his speech to call for a stamp duty discount for under-30s to help young people get a foot on the housing ladder, as well as a temporary period of zero rating for capital gains tax, to encourage investment and the sale of second homes. He said the state should move towards getting rid of the "deeply immoral" system which means taxes are levied several times on the same income. "It is time that we set a clear philosophical course and re-build an economy that is leaner, more agile and better prepared to compete in the modern world," Dr Fox said. However, the Prime Minister later rejected Dr Fox's calls for cuts to NHS budgets. During a visit to Milton Keynes Mr Cameron said: "There is one piece of advice that I won't take, and that is the piece of advice that says you ought to cut the National Health Service budget." The Prime Minister added: "There are many good suggestions coming from many quarters and as Prime Minister I'm never short of advice. Plenty of people are giving me advice and there is one piece of advice I won't take and that is the piece of advice that says 'You ought to cut the National Health Service budget'. We made a very clear promise before the last election that yes, we were going to have to take difficult decisions, yes, we were going to have to make some very difficult and painful cuts but we wouldn't cut the NHS budget. I think it's really important for people to know that. It's really important for people to know how much I care about it. The NHS was there for me and my family, I want it to be there for other people's families too. Dr Fox also failed to rule himself out of running for the Tory leadership in the future. Speaking to BBC Radio 4"s World at One programme he said "there is no chance of us having a leadership election in the Conservative party before the next election." "I think that would be madness," Dr Fox said. And I think we'd be far better concentrating our energy in discussing the policy proscriptions we have. However, when asked about his own leadership ambitions, Dr Fox said he would "see how I'm holding up" after Mr Cameron "stands down." "Since there is not going to be [a leadership contest], that's an academic question," Dr Fox added. If in 10 years time David Cameron stands down, I'll see how I'm holding up at that point.