A generation ago, one in 14 people was a member of a political party; now the figure is not even one in 100. Nearly half the electorate identified very strongly with a political party. Today fewer than one in six do. This is not just because society has changed with declining class identity and less tribal loyalty. It reflects the activity of the parties themselves, who, first Tory then Labour, adopted the Saatchi and Saatchi model of organisation with a strong centre controlling a tightly organised marketing and advertising machine, funded by a small number of very wealthy donors.

As a model for winning elections this worked well for a time. It also coincided with some genuine moves to empower party members – like direct involvement in electing the party leader. But even these moves to openness were overshadowed by a much stronger tendency to control and manage and it left the parties hollowed out – far less able to recruit new blood or to renew.

What’s been learned about trust in public bodies should have sent a very strong message to political parties as they replaced their conversations on the doorsteps with megaphone campaigning. Over the last few decades public trust in the institutions people talk to day-to-day and face-to-face has stayed strong – doctors, post offices, the police. Yet trust in big, distant organisations – big business, big government, big media – has declined.

But we need political parties. When people were asked which organisations have the most impact on meeting their long-term needs, political parties got the backing of one in four people, third only to government and public services such as the NHS, and beating trades unions, charities and business.

Recommendations like those of the Power report, which advised bypassing political parties, miss the point. Parties do things that nothing else can. They synthesise a coherent strategy out of competing priorities, they develop political leaders and they provide a simple shorthand of values for voters. Above all, they help to keep politics straight by providing a continuing mechanism of accountability in between elections. Countries which lack strong parties and depend on candidate charisma and petty, short-term rewards for sections of voters have more corrupt political systems than in Britain, and the people who lose out are the voters.

The people who responded to our research know how they want parties to change; 54 per cent want to see more involvement of people in local decision-making. They want parties to listen to the public, and to put more effort into explaining their values. In short, the public message is clear: the long trend towards nationalisation and top-down control now needs to be reversed.

The review of party funding provides an opportunity to deliver this. We propose changes which would separate the work that parties do in the locality and as civic institutions from the heavy artillery of national advertising. Activities that can be shown to be for the public good should attract public subsidies tied to voter involvement, in the form of tax breaks or matched funds for small donations.

Political parties need to rebuild their local roots mobilising able and energetic people as civic entrepreneurs in their communities rather than just being transmission belts for head office. I know that most people in the leadership of parties respect the foot soldiers who slog away all year round contacting voters and engaging with community groups. But they haven’t given them power. Now that the scandal of cash for honours and party funding crises have forced parties to look inwards, we need to encourage and reward active members. They are the people who sustain the relationship with voters which is at the heart of party politics.