LONDON - Britain's biggest retailer Tesco said on Wednesday it would not be prudent to give financial guidance for the 2020-21 year due to uncertainty caused by the coronavirus emergency.

However, it estimated the impact on its retail cost lines at between 650 million pounds ($800 million) and 925 million pounds, including significant cost increases in payroll, distribution and store expenses.

And it said if customer behaviour were to return to normal by August it is likely that the additional cost headwinds incurred in its retail operations would be largely offset by the benefits of food volume increases, 12 months business rates relief in the UK and prudent operations management.

($1 = 0.8124 pounds)

(Reporting by James Davey) ((james.davey@thomsonreuters.com))