What's the correct for of address for a female councillor?

[Legacy]

Am writing a letter. I have seen both of these used:

Dear Councillor Mrs X

Dear Councillor X

Which is correct?

Also do you ever shorten it to Cllr rather than use in full

I work for a Local Authority - all the Councillors (male and female) refer to themselves as Councillor X. They sometimes abbreviate, but I wouldn't in formal correspondence.

HTH.

agree with stinky feet
It would be Councillor X (regardless of whether male/female). That's what ours are referred to as in documents or on paper work.

I would use Cllr on the front of an envelope

As in
Cllr X
Council HOuses
Silly Street
NOwhere Land

And then start the letter as Dear Councillor X

(I too work for a council).