@Demolition of Democracy
"Let's suppose MPs do need to be vetted. What happens if an MP fails to pass the test?"
Nothing that shouldn't happen to anyone else - they just don't get to kiss babies or hold photoshoots outside the local school. I don't see that failing an eCRB bars you from acting as an MP - just from having contact with children. [Though I do like the idea of their criminal records being in the public domain].
All the other abuses of CRB checks need to be stamped out.
These CRBs were introduced to protect children and vulnerable adults and, frankly, that is ALL they should be used for. Full Stop.
Having said that, with any database you are going to need a test data set. I propose that for any government initiated database, the test data set be derived from serving MPs (especially ministers), life peers, senior civil servants and the families of the aforementioned. The test data will NOT be removed when the database goes live. By pre-loading the database with such people we might, possibly, ensure that the data is then protected adequately.