HeighHo .... you have a degree in economic, I didn't even get an 'ology in the subject, but as Quantitative Easing was emergency pumping money into the banking system - by the BoE buying UK government bonds (Gilts) from the market via their own (never used before) account - with the medium term objective of selling those Gilts back to the market, thereby reducing the money supply, potentially 'borrowing for nothing'?
Firstly assuming that the Gilt market won't react badly (selling off) to a government policy of placing debt on a central bank balance sheet rather than issue more Gilts, if the UK government had bought Gilts at an average yield of say 2% and sold them at say 5% (as bond prices move in the opposite direction to yields) and we have the lowest Base Rate for over 300-years - there would be a huge capital loss, even after getting a coupon of diddly squat.
And don't forget, many government departments like the NHS already have huge annual service bills for the next 25-years, on previous Labour borrowing on the 'never never'.
“Crippling PFI deals leave Britain £222bn in debt”
www.independent.co.uk/money/loans-credit/crippling-pfi-deals-leave-britain-222bn-in-debt-10170214.html
”Every man, woman and child in Britain is more than £3,400 in debt without knowing it and without borrowing a single penny – thanks to the proliferation of controversial deals used to pay for infrastructure such as schools and hospitals.”
I think you'll find that the Conservatives are investing in infrastructure e.g. railways, and more importantly, getting the private sector to do so, spending their money, at their risk.