Clazsmiff: to which Passport Office did you mail your application?
There’s nothing to stop you ringing the Passport Adviceline (0300 000 2222). You will be put through to a human being and then you can explain your problem. They may not be able to offer much assistance but on the other hand you may get a hint of whether there are any signs of normality beginning to resume.
rob’s application (above) took about 35 working days from the day his application entered the processing queue (taking into account the various bank holidays that have happened). On that basis you might hope yours would reach the same point on 29 May. But who knows?
I have learned from some newspaper articles that some passport staff were reallocated to processing universal credit applications in April. I have no idea whether that is still happening and/or whether those involve staff who are working from home.