Why lobbying?

Under the public relations umbrella, lobbying is a growing industry in the UK and it is now estimated to be worth £1.9 billion and employ 14,000 people http://www.hansardsociety.org.uk/node/view/707. However, it is an industry that has been marred by sleaze and scandal over the past 50 years. I'm going to look at its past, present and future existence in the UK. Will the industry continue to grow and will it lose the bad reputation it has managed to acquire?