LONDON (Reuters) - British retailers have endured another difficult month in March but are optimistic of a sales surge in April, when COVID-19 lockdown restrictions are due to be lifted partially, a survey showed on Thursday. The Confederation of British Industry’s monthly gauge of retail sales was steady at -45 in March. A Reuters poll of economists had pointed to a small improvement to -37. However, expectations for sales next month turned positive for the first time since December 2019. “Retailers are looking forward to April with a sense of optimism, given the potential re-opening of the sector across the UK,” Ben Jones, principal economist at the CBI, said. “Expectations point to a fairly muted recovery, especially when considering that base effects will tend to flatter annual growth next month, given the historic drop in sales in April 2020.”