LONDON (Reuters) – British businesses became more downbeat about the economic outlook in December, with the biggest monthly decline in confidence in more than a year, a survey showed on Thursday, adding to signs of a slowdown in the country’s economy. The Lloyds Bank Business Barometer, which surveyed 1,200 firms across the economy, fell by seven points to 35% from November’s 21-month high of 42%, and the largest monthly fall since August 2022. Thursday’s reading was still above the survey’s long-run average of 28%, but heading in a downward direction. This contrasts with the similar composite…