Best source of UK Data (FTSE all Share)

Has anyone got advice for sources of UK data - ideally FTSE All Share? Preferably with delisted included. Thanks

You have to at least tell what data you are interested in - EOD or RT streaming. Thats huge difference. Please follow this advice: How to ask a good question

Secondly, use SEARCH (magnifying glass) before posting because typically someone else already posted the answer.

For example London Stock Exchange EOD data: