According to the article, a fine of up to £500,000 could have been imposed and, given the seriousness of the breach, I think, the £30,000 fine is derisory. Of course, most people are aware that the Telegraph has a strong Conservative bias but I think directly contacting individual readers in an effort to strongly influence their voting choice is totally unacceptable.
I don't agree with Clarke's view that even if an employee has done nothing wrong it should still be possible to fire them. There have certainly been noises supporting that point of view but, fortunately, at the moment, as long as a permanent employee has worked for an employer for over two years he/she cannot be sacked without grounds laid down under employment law. This includes, I believe, that if an employee, through their behaviour, brings their employer into disrepute then they can be dismissed. Hopefully at some stage this will happen in relation to this man but if the company did not follow employment law then presumably it would be in breach of employment law/contract.