British retailers begging Santa for a Brexit deal for Christmas may be getting what they asked for.

The crucial holiday shopping period, which accounts for a large proportion of their annual profit, is always nail-biting for store chains. This year, it is inextricably linked to Britain’s departure from the EU.

With a Brexit divorce deal in hand, fears of a no-deal split have receded. Crashing out on October 31 would have been disastrous. By contrast, a deal — assuming it gets through the UK parliament — has the potential to bring a feel-good factor for retailers. It could unleash some pent up demand, particularly for big ticket items, such as fitted kitchens and sofas.

Consumers have held back from splurging on such things, even though wage growth has been outpacing inflation. Demand has already picked up this month, thanks largely to colder weather compared with a year ago. That may bode well. But, there’s still plenty of uncertainly that could weigh down the festivities, including the possibility of the current deal collapsing, a referendum to confirm it, or a general election being hastily called.

For the past couple of years, consumers’ anxiety over Brexit hasn’t been at a constant level. It has ebbed and flowed with the sense of crisis in government. In September, the volatility was so extreme that some retailers could even predict their sales based on that day’s headlines.

Even if Christmas does turn out to be better than expected — because a Brexit deal has been struck and an election delayed until 2020 — that doesn’t mean plain sailing from now on

The collapse of Thomas Cook, another jolt to the consumer sector, didn’t help either. Any election campaigning on crucial shopping days would be equally distracting, particularly for affluent Britons fearful of a Labour government led by Jeremy Corbyn. But all year the British high street has been battling cautious consumers, as well as the rise of online shopping. Even internet-based retailer Asos has been hurt by nimbler rivals.

Whatever happens with Brexit, the prime holiday shopping period will fall late. Christmas is on a Wednesday this year, providing a full extra weekend in December to shop ahead of the holiday.

Black Friday, the crazy US shopping tradition that’s taken the world by storm, is at the end of November, a week later than in 2018. Over the past five years, the price-slashing event has sucked forward about £2bn of spending from December into November, according to Richard Hyman, the independent retail analyst. It is always hard for stores that have discounted over the Black Friday weekend to return to full price for Christmas. This year’s timing makes it virtually impossible.

Even if demand isn’t disrupted by another Brexit hiatus or an election, there is the potential for discounts running from the end of November through to the holiday. It’s going to be hard for chains to hold their nerve.

Brexit means forecasting Christmas sales is even more difficult than usual, however, Hyman estimates that non-food sales will fall by 1%, while food sales will be flat, both a deceleration from 2018. If he’s right, it would be the first drop in December non-food sales since the referendum. Given that the level of discounting is likely to be intense wherever sales land, they are likely to be less profitable.

Amid this environment, what is certain is that the discount sector will do well, in food and fashion. The UK arms of the German discounters Aldi and Lidl are making efforts once more to prevent customers defecting to one of the big British supermarkets for their main holiday shopping. Upmarket and vegan food products will be a particular feature of their festive offering. Associated British Foods’s Primark, which has been elevating its gift selection and party dresses over the past few years, should also do well.

Mid-market chains, such as Marks & Spencer could find life tougher, even as some of their competitors are weakened. The privately owned John Lewis Partnership is preparing for even its more financially comfortable customers to be cautious, with plenty of gifts less than £20 such as Fever-Tree gin & tonic Christmas crackers and so-called experiences, such as personal shopping and spa days.

Although they are more expensive, at about £100, consumers may feel they are getting more for their money than when they buy traditional gifts.

And even if Christmas does turn out to be better than expected — because a Brexit deal has been struck and an election delayed until 2020 — that doesn’t mean plain sailing from now on.

The political wrangling is far from over. What’s more, three years of uncertainty have taken their toll on business investment. Britain shed jobs over the summer for the first time in two years. And let’s not forget any impact from a global slowdown in 2020. Consumers make the most drastic changes to their spending when they are made redundant or they see friends leaving the workforce.

British retailers should extend their Christmas wish list to what happens in the New Year too.

• Felsted is a Bloomberg Opinion columnist covering the consumer and retail industries.