Insurance company not paying out my curtailment claim for UK citizen returning from France on 16th March [solved]

AFAIK hotels are classified as essential establishments in France with regards to the epidemic, so they are allowed to remain open.

You should clarify with your ski resort whether they are in fact an hotel and whether they were ordered to close or decided to close. You might be entitled to a compensation in both cases, but citing the wrong claim reason ("recommended evacuation" instead of "accommodation unavailability") is going to complicate matters.

Your policy will cover you for a range of different risks. Curtailment due to FCO advice will be just one of them. Don't expect the insurance company to do your job for you and find an alternative ground on which to claim. Read the policy in its entirety and see what you are covered for. For example, it if you had a winter sports travel insurance, it is likely that you are covered for ski piste closure and you may be able to claim under that.

The bottom line is that we can't give you proper advice based on a very narrow quote from your policy wording. You should pursue all the options described in this answer whilst also looking for other ways you may be covered.

The policy is a contract between insurer and insured. If what you quote from your policy is all the policy says about such things then that was all you paid for and your claim seems unlikely to succeed.

Your policy likely says that you must call the insurer before making different arrangements. You say you tried but they did not answer. In the circumstances it might be considered unfair to hold you to that. Many people would have been calling them.

Can you get in touch with the accommodation provider for a statement that you were asked to leave?

I think the first link in your comment is to the first decree, published on 17th March following Macron's statement on 16th, which is too late for you. For your timeline you need the PM's statement at 8pm 14th March that the country must close all non-essential locations, notably cafes, restaurants, cinemas, nightclubs and shops from midnight. The decree refers to that.

Expect long timeframes: in the present circumstances insurers and the Financial Ombudsman Service are experiencing above normal demand from the public and have shorter opening hours, fewer staff.

I am afraid that although your move was understandable and probably the right one, and it may seem unfair to you, the insurance is probably totally right because you did not fulfill the conditions of the contract. In fact, you have probably broken the law.

The decree (fulltext in French) says nothing about leaving the country. It says that you are not to leave the house, except for work, for making groceries, or for health concerns or imperative family matters, helping vulnerable persons and children.

So, in the strictest sense, your leaving the country for no "good" reason was arguably against the law (since you left the house without any of the forementioned).

In any case, neither FCO nor WHO, nor a similar body (French government is not in any way similar) said anything in particular, let alone "Brits leave France now".

On the contrary, the French government explicitly provided prolongation of visas with the law of the 24 march. Although as UK citizen, you do not need a visa, the intention is clear. It is the exact opposite of "everybody leave, now!". It means "stay where you are, even if your visa expires, you will not be ciminalized for that".