http://www.ucu.org.uk/index.cfm?articleid=3680
Until recently London Met was 'grey-listed' which means that all members of the academic community were asked not to go to conferences/accept jobs/do collaborative work etc with the uni because of the decisions of managers to sack a large number of staff to recoup money lost for being fined for over-recruiting undergraduates. Or something like that. I don't think this bad behaviour will affect the way in which employers will think about London Met, you may just not want to go to a uni that behaves in this way. Kingston is alright. maybe a bit more prestigious than London Met, and I dont know what UCA is.
For your MA I think it is important to attend a good university, more so than for your PhD (where the reputation of your supervisor matters most). But often these charge more for their fees and there is certainly a sense that some courses 'sell' places on their courses to high fee paying students, and hopefully employers recognise that.
Maybe people on this forum are from London Met and can advise as to their experiences?