Usual caveat: I am
not a qualified financial adviser...
The most sensible thing to do will be to talk to an
independent financial adviser. The Pru people will not be able to help you as they are (probably)
tied, i.e. they can only advise on Pru products. Take personal recommendations from friends/work colleagues/family or you can get a list of local IFAs from
this site (there are others).
Choose an IFA who will act on a
fee-basis - you would engage a solicitor on the same basis - rather than a commission basis.
Do as much preparation as you can in advance - collect all the paperwork, sort it out by pension/provider and put it in chronological order - anything that makes it easier to understand and will also minimise the amount of time the IFA will need to research your position and then advise you.
A lot will depend on how close you are to retirement.
Multiple funds can be a good thing - diversification, risk management etc - but as you close on retirment it will be simpler to have them all in one place; there may also be benefits in knowing exactly what you have and whether or not you need to make additional contributions into the State pension system.
I could go on, but talk to an IFA - for a secure and organised retierement, it will be worth spending a few hundred pounds now.