This week's financial turbulence provides the starkest demonstration yet that we are living in an era of dramatic global change. Financial markets across the world are in uncharted waters. The British economy prospers as a global hub for investment, trade and services. That openness is a source of strength. But it also means that we cannot insulate ourselves from the contagious effects of the financial crisis in the United States, and the sharp increase in world commodity prices.
Nobody should underestimate the severity of this crisis. The US government now owns much of the US mortgage market and a large part of the world's biggest insurer. Two of Britain's biggest banks and mortgage lenders have had to merge. These are events of historic significance, and they demand firm and decisive leadership.
That is why all the efforts of our party and our government must be concentrated on the needs of the British people, whose paramount concern is how this week's events will impact upon their families, and how we can help them through this crisis.
Just as when we stopped Northern Rock going to the wall, we took the necessary and decisive action this week to protect stability and keep the financial system moving. We have acted to secure people's savings, support the housing market, and underpin liquidity in the banking sector. And with our support, the Financial Services Authority has banned short-selling of financial stocks.
I would have liked a national consensus on that measure but - as with Northern Rock - the Conservatives offer partisan criticism. While much of their image has changed, the Conservatives' instinct is still for government to walk away rather than intervene. Last year they even proposed to abolish mortgage regulations, saying the banks should be left to their own devices and simply "nudged" to act responsibly. You cannot "nudge" your way through a financial crisis.
In days of higher growth we reduced the national debt to give us the flexibility to increase borrowing in these hard times. Thus we are able to give a £120 tax cut to every basic-rate taxpayer, increase our winter fuel payments to pensioners, and step up government funding for homes, schools and hospitals, so that our capital investment, and the jobs that depend on it, continues.
The Conservative party's ideological objection to higher borrowing - coupled with its insistence on prioritising a £1bn inheritance tax cut for the top 3,000 estates - would have required it to scale back public services.
People are beginning to see again that politics is not a permanent referendum on a government, but a choice between competing philosophies.
It is only a Labour government that is able to act now to tackle the instability in the economy and provide the security that businesses and families need. This is a new agenda for an active government that stands for fairness first.
But let me be clear: this is not the moment to junk the economic policy framework that has secured sustained growth, high employment and low inflation over the past decade. The progressive British model that New Labour has pioneered has been successful. Our fundamental claim - that it is not just possible but necessary in the modern world to combine economic dynamism and social justice - remains as valid today as in the early 1990s.
So while we respond to a world that is changing all around us, our values of fairness and social justice remain our guide. Everything we have done since 1997, and everything we do this week in Manchester, is driven by one thing: our united commitment to fair rules, fair chances, and a fair say for all.
Gordon Brown, the prime minister of the United Kingdom.