There have been well documented problems at the DVLA. The bosses blame the unions and the unions blame the bosses.

"This week the DfT admitted in response to a parliamentary question that there were 56,144 applications for vocational driving licences – for lorry and bus drivers – awaiting processing. It said of these, about 4,000 were for provisional licences, while the “vast majority” were for renewals. In most cases, drivers could continue to drive while the application was being processed.

The DVLA said provisional licences were being issued in about five days but conceded that “more complex transactions”, for example if medical investigations were needed, may face “longer delays.”"

The Guardian