Black Friday gave supermarkets only a limited boost as shoppers delayed their Christmas preparations amid the uncertainty of the General Election, till figures show.

Sales growth at the UK’s grocers slowed to 0.5% compared with last year over the 12 weeks to December 1, with consumers making one less visit to the shops on average than this time last year, Kantar said.

Amid the uncertainty of the election, a lacklustre Black Friday and a wet autumn, shoppers have been delaying their Christmas preparations and are waiting to stock up on festive supplies, the figures show.

Sales of Christmas puddings and seasonal biscuits were down 16% and 12% in the past four weeks compared with this time last year.

However, consumers spent £28 million on advent calendars, up 1%, while sales of fresh and frozen party food rose 7%.

The number of people claiming to take advantage of Black Friday this year fell to 53% from 57% last year, with signs of “promotion fatigue” among consumers, an increased scepticism regarding the value of the deals on offer, and some retailers pulling back from the day all together.

The event is always less significant in the supermarket calendar and this year only 5% of Black Friday deal-hunters bought something from a grocer.

Fraser McKevitt, head of retail and consumer insight at Kantar, said: “We’re yet to see consumers ramp up their spending in the run-up to Christmas and, as anticipated, Black Friday only brought a limited boost for the grocers.”

Lidl and Aldi were the quarter’s winners, with sales growth of 9.3% propelling Lidl to a new record high market share of 6.1%.

Aldi’s year-on-year growth of 6.2%, worth £129 million in additional sales, takes its market share to 8%.

The four largest grocers came under further pressure, with their collective market share dropping to 67.7% from 69.1% this time last year.

Tesco was the best performing of the largest grocers over the past 12 weeks despite sales falling by 0.8%. Sales at Sainsbury’s were down 1.1%, while Asda dropped by 1.9%. Morrisons’ share of grocery sales dropped back 0.4 percentage points to 10.1% as sales declined by 2.9%.

Ocado continued to be the fastest-growing grocer, with sales 13.7% higher than this time in 2018.

Nielsen also reported an “unexpectedly slow” start to the festive period, with sales growing by just 0.2% in the last four weeks.

Mike Watkins, Nielsen’s UK head of retailer and business insight, said: “Though it has been a disappointing start to Christmas, we must remember that around one third of shoppers never intended to start their Christmas grocery shopping until December.

“A late surge in sales is quite possible this year as Christmas Eve falls on a Tuesday.”

Josie Clarke is PA Consumer Correspondent.