I completely understand why so many of you lose faith with politicians. So many of us argue for one point of view and then in what seems like the blink of any eye we seem to be able to believe in the complete opposite.

A brilliant example of this is the recent announcement that the government now wants to go ahead with a third runway at Heathrow. One of the first announcements made at the start of the new coalition government in 2010 was that the plans for a third runway at Heathrow were being scrapped. This was what the LibDems promised in their manifesto and I was really pleased when we were able to deliver on it.

The then prime minister, David Cameron, had told a meeting in London before the 2010 general election that “no ifs, no buts” there would be no expansion of Heathrow. So although the LibDems clearly played a significant role in the decision to scrap the plans it was not entirely without the support of the Conservatives in government with us.

I know that our current prime minister was one of those Conservatives who also spoke up against the plans. But now, surprise, surprise, all of those commitments have been abandoned and we are being rushed towards the arrival of bulldozers to demolish all the homes that stand in the way of a third runway to the west of London at whatever price to our environment.

I gather that all the negative comments that Theresa May has made herself over the plans for the third runway in the past have “mysteriously” been removed from her website. This is really treating voters as if they are idiots. Our current foreign secretary has promised to lie down in front of the bulldozers if and when they arrive on site. I just wonder how likely it is that he will ruin one of his very expensive suits to do this or will it be yet another commitment that we can take with a pinch of salt.

I know that the LibDems have not been the best at sticking to our manifesto commitments but you can be certain that we learnt from this bitter experience. Now if we commit to something we most definitely stick to our promises. From what I heard on the doorsteps of Witney, where we went from the fourth party to the second one and reduced the Conservative majority from 25,000 to just over 5,000 votes last week, many people seem to be starting to have more faith in us than our rival parties.

With the resignation of the Conservative MP for Richmond Park we have another by-election looming and another chance for people to judge which political party they have the greatest faith in. It would be wonderful if we could persuade even more people in that part of London to believe in the Lib Dems. They have in the past, and I will be doing all I can to persuade them that they can trust us again.