Retail will dominate the agenda this week as investors focus on turnaround efforts at Tesco and Debenhams and the digital revamp at Argos.

Tesco will reveal a steep fall in half-year profits on Thursday in the wake of a catalogue of disasters including a £250million accounting error that has seen eight of its executives suspended, and on which it is due to provide an update alongside its interim results.

Publication of the figures was put back by three weeks after the group admitted last month it had overstated its expectations of earnings.

This resulted in a third profits warning in as many months for the beleaguered group and a fresh headache for new chief executive Dave Lewis just weeks after he took over from Philip Clarke.

Tesco’s shares have fallen by nearly 30% since the end of August and are worth half as much as a year ago. Mr Lewis was drafted in from Unilever after Tesco’s worst trading performance in four decades, a first quarter like-for-like sales decline of 3.7%, sparked his predecessor’s departure.

The group is caught up in a supermarket price war as the major grocers battle the threat from discounters Aldi and Lidl and Mr Lewis has endured a bumpy ride since starting as chief executive on September 1, a month earlier than planned and just days after Tesco announced it was cutting its dividend by 75% and slashing spending on store refits by £400m a year.

Cantor Fitzgerald analysts said this could give Tesco a £1.3billion war chest to face down rivals in the price war.

However, Cantor’s Mike Dennis said the investigation, which could see supplier meetings postponed, might disrupt the business and “create operational paralysis” in the pre-Christmas period.

However, analysts have welcomed a decision to beef-up Tesco’s board with the appointment of Richard Cousins, chief executive of catering giant Compass, and former Ikea boss Mikael Ohlsson.

Attempts by Debenhams to drive better returns from its stores will be in the spotlight when the chain reports lower annual profits on Thursday.

The group, which has 158 outlets in the UK, is battling to improve its fortunes after a disastrous Christmas performance led to a sharp fall in first-half profits.

Admitting recently that 10% of its UK space was under-performing, the chain has invited Sports Direct and Costa into its stores as part of a trial that could lead to the arrival of a number of other leading brands.

The chain has struggled to keep pace with John Lewis which has outshone rivals because of its strong website, attractive stores and more affluent customer base.

At the time of the poor half-year results chief executive Michael Sharp said he wanted to make the business less reliant on discounting to pull in trade. Investec Securities is forecasting a 21% fall in Debenhams’ full-year profits to £110.2m.

Home Retail Group’s digital turnaround strategy for Argos should show further signs of paying off when it reveals higher half-year profits on Wednesday.

The group, which also owns DIY chain Homebase, is expected to post a pre-tax profit up 26% on last year to £34.6m, as it reduces its dependence on laminated catalogues in favour of iPads at Argos’s 747 shops.

Argos has embarked on a £300m five-year plan to revamp the business by 2018, as it gets to grips with competition from a combination of supermarkets, Amazon, Dixons and department stores. The revamp also includes fast-track queues for customers to collect online orders and modern stripped-back interiors in the chain’s stores.

Online retailer ASOS will see annual profits fall sharply on Tuesday after a year which has seen two profit warnings and a warehouse fire.

The fashion website is expected to post profits of £45.1m, almost 18% down on a year ago, after it investing £68m on assets such as a new hub in Berlin, expanding a facility in Ohio and a new warehouse in Shanghai.

ASOS was hit by a fire at its main warehouse in Barnsley in June affecting 20% of stock in the five-storey building. Insurers will pick up the tab after the blaze resulted in between £25m and £30m in lost sales.

However, it has also issued two profits warnings after it saying it needed to make a further significant investment in IT and to adjust the pricing on its websites in countries such as the US, France, Germany and Spain.

The business, which has been impacted by the strong pound, said as a result of this investment its profits next year will be similar to this year. As a result Nomura cut its forecasts for 2014-15 to £48m from £60.6m.

Its final quarter trading statement in September showed UK sales up 33% on a year ago, with strong sales in the European Union, but US revenues were flat and its rest of the world sales declined.