In my talk on newspapers for genealogy last Saturday I dealt mainly with Canadian papers, but have promised to add material on British papers to a forthcoming presentation. Previously I've recommended going to the British Library catalogue, newspaper subset advanced search here to find out what newspapers exist for a particular location and time. That remains a good option.
On Monday I went to LAC to investigate newspaper resources and was amazed to stumble upon a treasure tucked away amongst the reference books beyond the double doors to the west of the main reference area, room 222. It's Canadian!
The Waterloo Directory of English Newspapers and Periodicals, 1800 - 1900, is a 20 volume set. It has 50,000 entries, a total of 9,000 facsimile title pages and includes 48,000 personal names including every name in the DNB and Modern English Biography associated with a Victorian periodical.
I looked up Hackney in London and found numerous entries, including some really obscure ones.
There are complimentary volumes for Scotland and Ireland; I suspect the English volumes include Wales.
These are publications of the North Waterloo Academic Press. They also offer an online edition, priced for institutions. Get more information here.
Your best bet for access is likely at the nearest really good library, I checked several universities, Carleton, Queens, Toronto, each of which had it in their catalogue.