Top grocer Tesco is expected to provide evidence of how tough retail trading conditions are when it issues first-half figures on Wednesday.

Tesco is expected to disclose the worst UK underlying sales performance in 20 years as hard-pressed consumers keep a close eye on their spending.

The grocer, which last week initiated £500m of price cuts, is anticipated to post latest quarter like-for-like sales decline of as much as 2% in its domestic market, compared to a 0.1% fall in the previous quarter.

However analysts are not likely to blame Tesco group chief executive Phil Clarke, who took up his post in March, for the performance.

One analyst told the Sunday Times: “The team will be disappointed but Phil recognised the figures would be below par six months ago and they have already taken action.”

Tesco’s international business is likely to have sustained first-half performance and operating profit will be up year on year.

Sainsbury’s also reports quarterly figures on Wednesday.