"Winterval" is nothing to do with Christmas. It was a commercial promotion by that well known Marxist organisation, the Chamber of Commerce, in Birmingham to promote shopping between the months of November and February. It had nothing to do with politicians, leftie or otherwise.
It was called Winterval because it covered a lengthy winter period, where sales (outside of the Christmas rush) were typically low, to boost sales.
Christmas, of course, did take place during this period - at which point Birmingham City Council put up a big Christmas tree and Christmas lights, continued to hold their massive Christmas fair, had lots of signs wishing everyone Happy Christmas, sent employees cards wishing them a Happy Christmas, had a presence at the carol concert at various churches, and generally joined in with the Christmas spirit.
But you suckers fall for the Daily Mail headlines every single time. We've done this one, every year.