David Cameron meanwhile has sadly promoted other members of this reckless gang of deniers to positions of influence. Hence, we briefly had avowed sceptic and hater of windfarms, John Hayes, as energy minister. We still have an environment secretary, Owen Paterson, who declared on the BBC's Any Questions that climate change was not real, and Michael Gove appears to be systematically removing its teaching from the education syllabus.

The mood in the Conservative party, no doubt influenced by the rise of Ukip, is now so anti-science and irrational, that the new part-time energy minister, Michael Fallon, recently dismissed climate change as "theology". Small wonder investors in the low-carbon economy are spooked.

How has this come to pass? The answer is the same as for many issues the government is handling so badly: party leaders pandering to a small coterie of insiders. The public and large parts of industry remain strongly supportive of efforts to tackle climate change, despite the best efforts of some in the media to muddy the waters of scientific evidence. Ministers are giving license to those threatening to derail not just our own efforts to tackle the world's most difficult environmental problem but also those of the rest of Europe.

Although the LibDems are supposed to be having a moderating effect, the bill still has many flaws – and the scars of battles with the Treasury are evident. The proposed legislation does include some interesting, if undeveloped, ideas around supporting investments to reduce and better manage energy demand. But it is also very difficult to get a sense of the overall impact of the plans as they now stands.

Resolving one key issue would help bring some clarity about the overall purpose: whether or not a target should now be set, for significantly reducing carbon emissions from the power sector by 2030? The vote on a cross-party amendment in the Commons was only narrowly defeated. If in the Lords, the LibDems follow their own party policy, set only last year, a similar vote could be won. This would allow MPs to reconsider their position, and restore investors' confidence that there is a clear future investment path they need to follow.

Over the next few months, the bill will come under heavy scrutiny in Lords Committee, during which time more detail on the new market arrangements should emerge. Not least, information of on-going negotiations with EDF Energy, whose desire to build new nuclear reactors in the UK was the original impetus for the legislation. New nuclear is necessary and Labour supports the project – but not at any price.

Had we started out on this round of energy reform focused on how best to keep electricity affordable while addressing its environmental impacts, we would be working on a very different bill. One with clarity of purpose and a strong regulatory framework to protect consumers, with market forces then harnessed to dictate the solutions through increased competition.

Labour peers and others will work to ensure the final version of the bill enables the next Labour government to deliver on these outcomes. Then, hopefully, the hiatus in investment and the current culture of uncertainty in the sector will finally come to an end. Yes, the vocal minority opposing action on climate change will still be present at Parliament. But at least there will no longer be any risk of them being made ministers.

• Bryony Worthington is Labour's shadow energy and climate change minister in the Lords