Without a doubt, Caroline Lucas is, at least in parliamentary terms, a one-woman force for good. This pours out of every page of her book Honourable Friends? Parliament and the Fight for Change. She brings integrity and clarity, consistency and generosity to a parliament all too frequently devoid of all four qualities.

The beauty of Lucas’s book is not just in how easy it is to read, or in its meticulous weaving of issues together into a consistent belief system. The real beauty is in its generosity. Lucas walks you gently through the landscape of what ‘collaborative radicalism’ means in practice.

On issue after issue, Lucas passes the credit for her work to others. Sometimes these are parliamentary colleagues across different parties. Sometimes they are the staff in her office, who appear to have a galactic reach across issues that whole party groups in parliament often struggle to keep pace with. But most often Lucas passes the credit to groups outside parliament: those rightly identified as today’s driving force in the movements for progressive, inclusive and sustainable change.

So here is the most persuasive, profound and perverse lesson to be drawn from this report on her first parliamentary term: the best prospects for parliament come from those willing to act both within and without its reach.

Left to its own devices, the last parliament was an even more desolate place than ever; more in the grip of contra-democratic forces than democratic ones. As Lucas trails you through her campaigns against fuel poverty, privatisation, fracking, regressive drugs policies, the extension of student fees, and policies that would rescue the banks but not the poor, you cannot fail to see that today’s mainstream politics has walked away from radical collectivism. The contras are in control, not just of the machinery of government, but also of its mindset.

Nothing makes this clearer than Lucas’s demolition of the arguments used to deliver huge new subsidies to a nuclear industry facing ever-spiralling costs and ever-lengthening pollution liabilities. The Conservative–Liberal Democrat coalition had promised “no new subsidies for new nuclear”: nothing ambiguous about that. The problem was that nuclear lobbyists had become so deeply entrenched in parliamentary life that they met almost no opposition to a complete inversion of language and truth to secure a reversal of policy.

I’m not sure if there is a collective name for a gathering of fools or hypocrites, but Lucas came up with a dignified version. She describes the official Coalition euphemism for subsidies – “a market-based support mechanism” – far more accurately as “a dishonesty-based perception-changing mechanism”. In broader terms, this actually describes many of the policies driven through in her first term. It is a criticism that comes without grace or (political) favour.

Labour was as much a part of this nuclear lie as anyone else. They weren’t much better either on ‘austerity’, on the need for a Robin Hood Tax on speculative capital, or on tax policies that would keep carbon in the ground rather than encourage its exploitation.

What Lucas values (and acknowledges) is the existence of a parliamentary enclave of integrity that crosses party divides. This is the grain she has tried to work with. In doing so, she has also taken this solidarity into a broader, non-naive Europeanism. Her critique of UKIP exemplifies this. She criticises UKIP, but not on its narrow nationalism, or on the bile of its anti-immigrant tub-thumping. She goes to the heart of spurious ‘sovereignty’ issues, held as dearly by the Tory right as by UKIP:

“[W]hat we have is the odd situation where a whole political party, UKIP, has emerged which devotes itself to attacking the EU over sovereignty, but which shows no concern about the loss of sovereignty to NATO and the WTO.”

It is a criticism she quickly extends to the proposed Transatlantic Trade and Investment Partnership (TTIP) treaty, which would give corporations the right to sue citizens over anything that stands in the way of corporate profit-taking.

Against such real erosion of sovereignty, UKIP stands silent. But so too do the Conservative Party, the Lib Dems and Labour. The genuinely ‘honourable friends’ who stand against this are few in number. And this is where Lucas reaches her own limits.

As things stand, no one has yet been able to clone her. Parliament needs another 350 of her ilk to find the courage (and intellect) required to address the scale of challenges the planet urgently has to tackle. The biggest criticism of Lucas is the danger that she gives parliament an undeservedly good name. For, in truth, Britain’s parliamentary democracy is in a mess.

There is a face-off between austerity and austerity lite. Only the minor parties threaten to disrupt a status quo that fails to engage with the transformational times we live in. In the absence of big, visionary ideas, the public is treated to a playground politics of ritual abuse that, at its best, is boring. At its worst it is sleepwalking towards disaster.

Alan Simpson is a writer and campaigner on climate change policies. For 18 years he was the Labour MP for Nottingham South.