I am getting old. Like most old men I have a tendency to be grumpy and claim that things aren’t as good as they were in the old days. Please bear this in mind when you read this.

I was trained as a Commando officer so I don’t know any other means of tackling a challenge than fix bayonets and charge. I don’t really do subtlety. Please remember that, too when you read on.

I am an enthusiast, and have a tendency to paint in large shapes and bright colours. What follows is Gaugin, not Canaletto. Please make allowance.

When you read this please finally note that I have been a committed and passionate Liberal since a canvasser knocked on my door forty-five year ago and explained what we stood for. That day, I put on Liberalism like an old coat waiting for me in the cupboard and I have worn it ever since with pride – come what may.

In all those long years I have never glanced to right, left or centre for a better political home for my beliefs than our Party – and that remains the case still. So please understand, if the words which follow offend, they are written with love.

So, now you have been warned, here goes.

There are good things – really good things – to celebrate as we gear up for Bournemouth. We have a multi talented Leader who deserves our whole-hearted support. We have 12 MPs in place of 9 before the last election. We still retain thousands of new members and we are winning local Council by-elections at a good rate.

But – didn’t you just know a ‘but’ was coming? – nevertheless, the biggest danger for our Party at the seaside next week lies in glossing over the existential challenges which now face us. Unless we are prepared to be realistic about where we are, return to being radical about what we propose, recreate ourselves as an insurgent force and re-kindle our lost habit of intellectual ferment, things could get even worse for us.

Consider this. We are the Party who, more than any other, represents the progressive centre in our country (I prefer centre left, but I am not in the business of dividing here). That space has never been more empty, voiceless, vacant and uncontested than it was in the last election. And yet far from filling that gap and mobilising those in it, our vote went down to an even lower base. Not in my life time have their been conditions more favourable for a Lib Dem advance in a General Election. But we went backwards.

Now, with Labour and the Tories spinning way to the extremes, Britain is polarised as never before and the vast sea of people who share our beliefs, find themselves voiceless and silent.

Not all of them, sadly, are Liberal Democrats or want to be. Many belong to other Parties and many, many more do not belong to any party – or wish to, with party politics as they are.

Politics in Britain is unsustainable in its present state. The moderate, majority voice of our country, which usually determines elections, cannot be left so unrepresented. If we cannot, or will not be the gathering point for these, the new left out millions, then who will and what are we for?

Twice before in our recent history, others have moved onto our ground– once with the SDP and once in the early days of New Labour. Both times we reached out to these new forces and prospered as result. These days we look hostile to this possibility. We will be at very grave danger indeed if this should happen again in the near future and we stand aloof.

Our reluctance on this front does not just threaten our future. It also contributes to the disfigurement of our national politics. If we are to fulfil our historic role at a moment when liberalism is more at threat than ever in my life, then we have to be less tribal, more inclusive and more willing to engage others than we have sometimes seemed in recent years.

What does this mean?