For years I have been accumulating data about national voting intention opinion polls in the UK and have records of various sorts stretching back to 1943. I had previously held off sharing them as the data is not in a perfect state. However, given that perfection never arrives, I have decided to stop holding off and make the data available in case other people also find it useful.
I intend to update the spreadsheet once a quarter, both adding in the new polls in the interim and also improving the older data, such as filling in gaps and making some of the columns clearer.
You can find the PollBase database at https://www.markpack.org.uk/opinion-polls/