There is very little that small amounts can be invested in that will match inflation with low risk, with the uncertainty of Brexit UK shares are always going to be uncertain.
Don’t discount currency fluctuations, Sterling is low so hold on to cash, over the months it will increase as the uncertainty ends. This is why overseas investors are willing to lend at low rates when the pound rises they make money.
Larger investments, property has always been good, but increasing regulation and taxation will eat into any gain, bearing in mind that you may be a high rate taxpayer even that may not be worthwhile. So if the mortgage is paid off, your pensions are good and you have spare cash, spend it or give it away. If you have children or grandchildren that will benefit, that is probably better than leaving it in the bank at .25%.