Peter Whittle: Overcrowding is London's biggest problem – it affects housing, travel, and our safety

As everybody who lives here knows, London is the greatest city in the world. Time after time, in poll after poll, London outranks all competitors, on business, culture, food, people - everything. But we are facing today huge problems.

The chronic housing crisis, with soaring rents and sky-high prices putting property ownership out of the reach of a majority of Londoners is not just, as the other candidates say, an issue solely of building more homes.

It is a matter of demand too, and unless we address this, supply will never keep pace, and the housing crisis will never be solved. London tries to absorb 100,000 new arrivals each year. Promises made to build 200,000 homes in 5 years don't reverse the problem in any way, it merely slows the rate of overcrowding.

Of course, we need to build more houses. We should also prioritise Londoners in our social housing, and make it much easier for developers to build on brownfield sites.

But this will never be enough, unless we use the uniquely persuasive power of London, through the Mayor's office and the Assembly, to bring the point home to Government that we need to look at the demand side of the housing equation too.

Similarly transport in London is increasingly difficult, despite the daily efforts by those at TfL to keep London moving. Tens of millions of journeys take place but overcrowding on our tubes and trains increases year by year. The roads, clogged by thousands of private hire vehicles and interminable road works lose the capital millions of working hours and thus pile costs onto our businesses.

The Mayor can act to change this. I would campaign to stop the HS2 white elephant, the high speed train project which will tear up stretches of London and strip the transport budget of billions which can be better spent on improving the commuter network.

The Mayor can also push to make fares logical, for instance by introducing a 90-minute multiple-journey bus ticket, as I advocate, rather than penalise passengers who need to change buses.

And then there is security, which as a recent BBC poll showed is now, along with housing and migration, one of Londoners' top concerns.

Candidates in this election last year held up signs announcing "refugees are welcome", proclaiming that London should take in thousands, but without a thought as to who these refugees were and from where they came.

In the months since Sadiq Khan signalled his virtue, we have had the atrocities in Paris and Brussels. The murdering crew of Isis have in the last weeks published direct and pointed threats to our city. Would he still say welcome, knowing as he must that both those horrific events involved people who smuggled themselves into the EU via the so called 'refugee' migrant routes from Greece?

The head of Europol himself tells us that up to 5,000 trained radicals are now in Europe, people who will have access to European passports in just a few years, and therefore the right to travel and live here unimpeded.

Surely it is the clear duty of those who aspire to lead and govern London, to have as their greatest priority the safety of Londoners?

To do that we need to control our borders. To do that London needs to send a clear message to Government.

Peter Whittle is Ukip Candidate for London Mayor