A shopping spree on Tesco shares came to a halt this week as investors waited for boss Dave Lewis to set out his stall at next week’s prelims.

Impressed by Lewis’s early action in the face of disasters such as the accounting controversy, buyers have taken a gamble on the giant grocer.

From 188p at the beginning of January Tesco’s stock reached 251p earlier this month.

It has since fallen back to just under 243p at the time of writing.

There was a decline at the start of this week as worries such as potential writedowns and the scale of Tesco’s pension deficit spooked the City.

But important as such concerns may be – and strengthening the balance sheet is one of Lewis’s three big priorities - restoring Tesco’s fortunes will in the end depend upon whether it can reignite the retailing verve that powered its stellar ascent in the first place.

Priority number one is improving Tesco’s competitiveness in its core domestic market.

There are some reasons to be cautiously cheerful about progress so far.

The retailer has cut prices and communicated the shift clearly in-store.

Range rationalisation is underway, scaling back on the overabundance of similar product and devoting more shelf space to the most popular lines.

There have been efforts to improve availability and an emphasis on customer-facing roles and responsibilities in shops rather than processes and back-office duties.

When Tesco last updated in January, there were signs that the changes were starting to have an effect.

There was, for instance, like-for-like volume growth in fresh food for the first time in five years.

Next week’s finals would certainly not make the grade as Tesco Finest.

But if, at the retail level, there are signs that the under-pressure grocer’s shelf life is being extended, that should give greater confidence that other challenges can be successfully addressed too.