Excessive expenses are claiming the headlines as I write this. We have seen the Home Secretary misinterpreting the rules on second homes for her own benefit and then the disgraceful conduct of her husband watching porn films at the taxpayer's expense. Her agent claims that she is a very hard working constituency MP but that is no excuse for not keeping an eye on what is going on around her or on her behalf.

She is of course not the first and only example and probably won't be the last but steps have to be taken to stop the rot. Liberal Democrats have always pledged to tighten up the rules on MPs expenses, to make the system transparent and to punish abuse effectively.

I believe that big money has dominated politics for far too long. It was very interesting to see the reaction of the Conservative party this week when one of their big donors gave money to UKIP instead, as he didn't like their stance on Europe.

It is because Labour and the Tories benefit most from the system that they do not want it changed. They have both reneged on a crossparty agreement to reform the party funding system. Liberal Democrats do not believe that individuals and organisations should be able to 'buy' influence or peerages. We are the only party committed to taking the big money out of politics. We are committed to capping individual donations to political parties and to reforming trade union funding. We will also cap party spending at a local and at national level at all times during the electoral cycle.

I have heard little of the success or otherwise of Saturday's 'Earth Hour' when everyone world wide was encouraged to turn off all non essential appliances and to eat dinner by candlelight. Personally I found no hardship in this and in fact like to boast that it is my general practice to try not to leave unnecessary lights burning or leave my TV or computer on standby. We have grown to believe that lighting is essential for health, safety and security. I think that it is time to challenge some of the perceptions attached to this. I agree that there is definitely still a need to increase public knowledge of the amount of energy consumed and its relation to climate change both in our personal lives and in the wider world.

Finally there is a mixture of hope and fear attached to the outcome of the G20 convention taking place this week in London. My greatest hope is that really meaningful agreements will be made and my greatest fear is that the media and police predictions about the scale of protest and havoc will prove justified. No doubt it will at least lead to plenty of comment next week.