Supermarket sales growth slowed as the UK geared up for its first December election since 1923, according to the latest figures from Kantar.

Sales across the wider grocery market grew just 0.5% in the 12 weeks to December 1, 2019, as UK consumers tightened their belts ahead of the looming election.

The data showed Black Friday brought only a “limited boost” for grocery retailers, as only 5% of consumers bought something during the period from a supermarket or convenience store.

Kantar blamed election uncertainty, a lacklustre Black Friday and a wetter than average autumn for the slowing growth, and said “shoppers have been delaying their Christmas preparations and are waiting to stock up on festive supplies”.

Of the individual grocers, Lidl achieved a new record high market share in the period of 6.1%, propelled by sales growth of 9.3%. Aldi saw year on year growth of 6.2%, which was worth an additional £129m in sales.

The big-four grocers came under further pressure during the period, with their combined market share falling to 67.7%, down from 69.1% in the same period the previous year.

Ocado remained the fastest-growing grocer, with sales 13.7% higher than at the same time in 2018.

Head of retail and consumer insight at Kantar Fraser McKevitt 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.

“The number of people claiming to take advantage of Black Friday this year fell to 53% from 57% in 2018 with signs of ‘promotion fatigue’ among consumers, increased scepticism regarding the value of the deals on offer and some retailers pulling back from the day altogether. 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.

“With the general election now only days away, people are waiting to fill their cupboards for the festive break and sales of Christmas puddings and seasonal biscuits are down 16% and 12% in the past four weeks, compared with this time last year. But there are some purchases that just can’t wait – £28m was spent on advent calendars in the past four weeks, up 1%, and sales of fresh and frozen party food rose 7% as our diaries fill up with festive events and gatherings.”