The French are correct: if you are resident in France, it is to France that you should pay all your income tax, not to the UK, even though the income emanates from the UK – government pension income and rentals excepted.
Tax is a question of fact and not of choice.
It seems you have not transferred your fiscality from the UK to France using the HMRC form United Kingdom/France Double Taxation Convention (SI 2009 Number 226).
You should complete this and redo your declarations in the UK for 2018-19, 2017-18, and 2016-17 and in France for 2018, 2017 and 2016. There is little point in doing more as the French tend to only accept reviewing the last three tax years.
As a result, you will be correctly paying tax in France, not the UK.
While French income tax is generally more benign, France does have the social charges that it applies on income and gains at 17.2%, which could hurt if you have investment income.
Having said this, UK state pensioners in France with an S1 form for their health may currently benefit from charges on property and investment incomes reduced to 7.5% due to being deemed attached to another EU/EEA country’s social security system.
Reader's query answered by Hugh MacDonald
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