Issuing bonds in the period in which the pound is strong relative to the dollar and euro in an interest rate environment in which a guaranteed low return from a bond is very attractive to investors is the 'no brainer' thing to do. It must be approved through referendum in which the voter will vote, knowing the amount of bonds and their specific purposes(education, health etc.) By having a referendum will mot only guarantee their passage but give cover to the politicians who must propose it.

The public is used to borrowing long term mortgages on their homes and will recognize easily the benefits of masive bond financing as long as the society will be improved. The bonds issued must guarantee the investments in public services will improve the society significantly. In order to achieve this the financing in the UK nust be done on a programmed, massive basis over many years. Unfortunately without a referendum; it will never be done on the scale needed because the Bank of England was made 'independent' and the banks' governors and benefactors won't approve.  A referendum may be able to negate any pressure coming from the Bank of England but it would have been much easier to issue the necessary bonds if the Bank of England had remained answerable to a political party, in this case-Labour.

Your ideas of how to finance are noble but not 'realpolitik'. Massive focused bond financing of the 'state' is what built the infrastructure of the state of California through the massively financed university education system which is the most dynamic in the world having created or contributed to most of the improvements in our societies.