Retailers will take centre stage this week as high street bellwether Marks & Spencer updates on trading and faces shareholders at its annual general meeting, while investors will also gather for the Sainsbury's AGM to hear how its boss plans to turn the grocer around.

Marks & Spencer will show that its long-term recovery is still a work in progress when it is expected to post a fall in clothing sales at its first quarter results and annual meeting on Tuesday.

Brokers at Numis expect the retailer to report general merchandise like-for-like sales down one per cent, compared to a 1.5 per cent fall a year ago and 0.7 per cent rise in the previous quarter due to "unhelpful weather in May". The group's general merchandise unit is comprised largely of its clothing sales.

The firm's same store food sales are expected to lift 0.5 per cent, compared to a 1.7 per cent rise a year ago and a 0.7 per cent boost in the previous quarter, as the group's high-end items continue to outperform the grocery market, which is locked in a supermarket price war.

However, Marks & Spencer turned a corner in May when it posted its first annual profits increase in four years.

The firm reported underlying profits up 6.1 per cent to £661.2 million for the year to March 28, beating City expectations and easing some of the intense pressure its chief executive Marc Bolland has been under in recent years.

Mr Bolland took over at M&S in 2010 and during his tenure he saw rival Next overtake the annual profits haul at his business.

Under his leadership, Marks has poured billions of pounds of investment into the business to try to turn around its fortunes, while clearing out its top fashion team and recruiting celebrities for high-profile marketing campaigns.

Yet sales at the beleaguered general merchandise division continued to crumble - with 14 quarters in a row of like-for-like declines until a 0.7% lift in the previous quarter.

Items such as a much-talked about 1970s-style suede skirt worn by TV presenter and model Alexa Chung have helped improve the image of M&S's clothing range.

There was also disruption at its online distribution centre over the peak Christmas period, but the group said there had been good progress since then, with marksandspencer.com sales back in growth in the fourth quarter of the year.

Mr Bolland said in May: ''We are transforming M&S into a stronger, more agile business - putting the right infrastructure, capabilities and talent in place to drive our strategic priorities.''

Numis said "Marks & Spencer's strategy is looking increasingly robust", despite the downturn in clothing sales expected when the group hosts its annual meeting at Wembley Stadium in London on Tuesday.

Sainsbury's investors will want to know when boss Mike Coupe's plan to turn the supermarket around will take hold at its annual meeting on Wednesday.

Earlier this week the grocer saw its sales fall 1.3 per cent in the 12 weeks to June 21 compared with a year earlier, according to respected research body Kantar Worldpanel. This also saw its market share slip 0.2 per cent to 16.5 per cent.

On top of this Sainsbury's posted its sixth straight quarter of sliding sales last month as it suffers amid a fierce supermarket price war, and said it expects prices to continue falling into next year.

It reported a 2.1 per cent drop in same store sales excluding fuel in the 12 weeks to June 6, which comes on top of a 1.9 per cent fall in the previous three months.

All of this comes after Sainsbury's reported its first annual loss in a decade in May, falling into the red by £72 million after writing down £628 million on the value of its property estate.

The Big Four grocers are under pressure from falling UK food prices and a highly competitive sector as the main players scramble for market share, which is being eaten away by discounters Aldi and Lidl.

Chief executive Mike Coupe promised to ''match whatever our competitors throw at us'' after Morrisons fired the latest salvo in the price war last month, with new boss David Potts announcing that prices on 200 items including milk, butter and bread would be slashed by as much as a third.

Mr Coupe said in June he saw little sign of an end to falling prices.

He said: ''We will see price deflation continue until the end of this year, and into next year. This is good news for customers but puts pressure on our sales.''

Mr Coupe, who took over from long-standing predecessor Justin King last July, unveiled a wide-ranging plan to fight back against the discounters in November which included price cuts to 1,100 items and improvements in quality to 3,000 own-brand products.

He pledged to spend £150 million on cutting prices under the plans.

It said last year that a quarter of its stores have under-used space and over the next five years this will be used for concession partnerships and to expand its non-food goods.

Sainsbury's opened three Argos concession stores during its first quarter - in North Cheam, Nantwich and West Hove - adding it plans to open 10 by the end of the first half of its financial year.

ASOS is expected to post another strong quarter of trading on Tuesday as the online fashion retailer upgrades its IT systems and adjusts prices across its overseas websites.

The City expects the business to post retail sales up 21 per cent, compared to a 25 per cent jump a year ago, as tighter stock control and increased full-price sales more than offset investment in local pricing across its nine overseas websites.

Numis added that growth in the business will also be able to overcome the strong pound against the euro due to uncertainty in the eurozone and fall in the price of the rouble brought about by the crisis in Ukraine.

ASOS, which sells over 75,000 branded and own-brand products to 9.3 million customers, is midway through a two-year IT overhaul as it also looks to modify pricing across its regions.

The business has rolled out local pricing in Australia, France, Germany, Spain, Italy and the US recently, enabling it to sell goods at more competitive rates and sell brands which were previously restricted in these territories.

The firm continues to develop its German Eurohub warehouse, which accounts for 24 per cent of EU orders and is expected to increase to 35 per cent by the end of the year.

Chief executive Nick Robertson said: ''With our continued investment in our international price competitiveness gaining traction, momentum in the business is building."

Last June a major fire at its Barnsley warehouse caused short-term disruption, but the company was able to recommence trading within two days.