From 14 June, Clubcard points will be worth twice their value when customers cash them in, rather than three times as they are now.

The scheme enables shoppers to collect points for money spent at Tesco and exchange them for vouchers which can be used in store or for restaurant meals and day trips.

Sainsbury's and Boots also cut the value of loyalty schemes recently.

Some Tesco customers reacted with disappointment to the grocer's announcement, pointing out it came as supermarket prices were rising.

Jason Murray, from Stockport, said the perks offered by Tesco's Clubcard were the "only reason" he shopped at the supermarket.

He told the BBC from 14 June he will switch to Aldi and Lidl after thinking about it and comparing prices in recent months.

"I don't quite think they understand how much of an attraction their Clubcard is to their customers," he said.

"The customer is key and in my opinion holds all the cards. What I will lose via Clubcard I will gain via cheaper shopping."

One woman tweeted that Tesco's Clubcard scheme had "kept me shopping with you but now with your prices soaring and the announcement about the points changes I'll be looking elsewhere".

Another said reducing the rewards by a third made them "pretty redundant tbh [to be honest], hardly a reward at all".

In a message to customers, Tesco's chief customer officer Alessandra Bellini said the move would "make sure we can continue to provide you with a wide range of exciting rewards, whilst keeping our product prices low".

She also said the company was extending the time period that Clubcard rewards would be valid for up to 12 months, rather than six in order for shoppers to use points at the higher value before the changes come in.

The grocer first introduced Clubcard in 1995 and within a year, customers were spending 28% more in its stores. The popular scheme enables points to be spent at the likes of Pizza Express, Legoland and Alton Towers.

When Tesco last changed its loyalty scheme, dropping the value of some rewards and raising others, customers responded angrily to the move which was implemented immediately.

The grocer is not the only retailer to have made its rewards scheme less generous recently.

From May, Boot's Advantage Card holders will get 25% less for every £1 they spend in store, earning 3p rather than 4p.

In November, Sainsbury's Bank cut the amount of Nectar points customers could earn by 75%, from two points for every £1 spent, to one point for every £2.

Commentators say there has been a shift to instant discounts for cardholders rather than rewards for points collection across various retailers.

That allows companies to continue to collect valuable data about spending habits, while keeping their own costs down.

Differential pricing also allows companies to push their own-brand products, and have branded products supplied cheaper, to enhance profits.

Lisa Byfield-Green, data and insights director at trade magazine Retail Week, said just like households, supermarkets were facing increased costs and were "having to decide where to invest and where to cut back".

She said Tesco's Aldi price match scheme, Clubcard prices and Low Everyday Price initiatives had "come at a cost" for the business.

"As costs spiral, Tesco has already cut jobs at its head office and reduced the number of managers in its stores. It has closed service counters and at the same time will grant shop workers their third wage increase of the year next month."