M&S says the current retail outlook remains uncertain

The iconic retailer is due to issue a trading update on Wednesday with several reports tipping a like-for-like sales growth of between 1% and 3%.

However, analysts expect M&S's pace of growth to be its lowest since 2005.

The firm's shares fell by more than 4% on Friday as investors worried about the retail sector as a whole.

Dixons owner DSG and clothes shop Next have already reported poor festive trading, while furniture retailer Land of Leather has issued a profit warning.

However department stores House of Fraser and John Lewis both saw strong growth in the weeks before Christmas and into the New Year sales.

Other firms due to report this week include supermarket giant Sainsbury's, bakery chain Greggs and the Restaurant Group - which owns brands including Garfunkels.

Also this week, British Retail Consortium figures will give a broader picture of High Street sales for December - with analysts expecting growth to have slowed compared with the same month a year earlier.

Observers believe that higher mortgage payments and bills, along with nervousness about debt and the economy as a whole, have weakened UK consumer confidence.

Forecast cut

M&S, whose chief executive Stuart Rose was knighted in the New Year's Honours list, is set to report a rise in clothing sales but will say that food sales were lower than a year ago, according to The Observer.

And The Sunday Times has predicted that like-for-like sales at M&S will fall for the three months to 29 December - which would be the firm's first such drop in more than two years.

Earlier this year, the company warned that trading conditions would remain "very challenging".