Members of Parliament from the UK’s three biggest political parties in the House of Commons significantly overestimate levels of public resistance to major policy proposals for tackling climate change, a University of Cambridge study suggests.
Researchers say it may be the first data-led evidence for a “spiral of silence” in Westminster, where skewed perceptions of public sentiment among politicians can reduce political support for a policy.
The study’s authors, from the University’s El-Erian Institute of Behavioural Economics and Policy and the Cambridge Political Psychology Lab, surveyed one hundred sitting MPs in early 2025 on how they think voters and other parliamentarians feel about carbon reduction policies, and compared their estimates with public polling from earlier that year.*
On making grants or loans for improved insulation available to all households with an energy efficiency rating of C or below, MPs collectively estimated public opposition to the policy at around 18%, more than three times the actual level of just 6%.
When asked about rejigging tax on products so that it varies according to environmental damage, MPs believed public opposition to be around 38%, almost double the 20% shown by polling the British people.
“MPs across parties who both support and oppose climate policies consistently overestimate public opposition,” said study lead author Dr Lisa-Maria Tanase, who conducted the work for her PhD at Cambridge. “This is likely to limit the range of what they consider to be politically feasible options for taking action on climate change.”
“Our findings cannot be explained away by wishful thinking of politicians or the projecting of their own worldview. On average, even MPs who support a climate policy think the public is more opposed to it than it really is,” said Tanase.
“Politicians, like all of us, are often exposed to information environments that distort perceptions of public opinion. Social and traditional media can disproportionately reflect particularly vocal segments of society rather than the full distribution of opinion.”
“We find a ‘funhouse mirror’ effect through which politicians see a distorted version of the public position on carbon reduction policies, associated with a lower willingness to promote these ideas,” said Tanase, now a Postdoctoral Research Associate at Cambridge’s El-Erian Institute of Behavioural Economics and Policy.
False polarisation
MPs also believed the UK electorate to be far more politically polarised over carbon reduction – or “net zero” – policies than it is, according to the study published in the journal Communications Sustainability.
Polling showed a 12-percentage point difference in support for the insulation and product tax policies between Labour and Conservative voters, but MPs estimated it at more than double that, at around 25 percentage points.
MPs predicted the difference between Lib Dem and Conservative voters on climate policies at 30 percentage points, when polling put it at just 14 points. Even the small two-point difference between Labour and Lib Dem voters was estimated at nearly five points by politicians.
“A number of previous studies show that exaggerated perceptions of polarisation can reduce the willingness of politicians to engage in cross-party dialogue,” said Tanase.
This “false polarisation” was most evident for Conservative voters, who MPs considered to be far more sceptical of these climate policies than polling suggested.
MPs overestimated the divide by about fivefold, believing Conservatives were on average 12.6 percentage points less supportive than the general public, when polling showed it to be just 2.5 percentage points.
“Environmentally supportive Conservative voters may end up feeling misrepresented if politicians consistently exaggerate how different their attitudes are from those of other voters,” Tanase said.
Spiral of silence
In fact, how MPs perceived public support for a green product tax predicted their willingness to advocate for it, even after accounting for each MP’s personal belief in the policy, the study found. Parliamentarians who thought support among the electorate was lower were, on average, less willing to speak up for the tax in public.
Researchers also asked MPs to estimate how many other parliamentarians would back a green product tax. Again, believing it to have less support among colleagues across parties correlated, on average, with MPs saying they would be less willing to champion it in Westminster, regardless of whether they personally support the policy.
Tanase says the study provides some evidence of a “spiral of silence” among MPs, as perceptions of low support among the electorate or Parliament reduces their willingness to speak up for a policy – even if it’s one they support. This suppressive effect is policy-dependent, as it wasn’t detected for insulation subsidies.**
Researchers found that parliamentarians not only overestimated opposition, but also markedly underestimated public support for the climate policies.
MPs underestimated public backing for an environmental product tax by 14.9 percentage points and underestimated support for the energy efficiency policy by 7.1 percentage points. Overall, MPs underestimated public support for these climate policies by about 11 percentage points on average.
However, the study suggests MPs’ beliefs about public opposition to climate policies are more influential. “Overestimating opposition is likely to generate greater political risk aversion than assuming the public is merely ambivalent,” Tanase said.
The researchers found all these misperceptions to be so potent that when they randomly assigned half the MPs to receive public polling results, then asked them to estimate support for another set of climate policies, it barely moved the dial in reducing inaccurate estimations.
“Our study found a systematic pessimism about the public appetite for climate action among the UK’s most influential decision-makers, and evidence that it affects their intended behaviour on climate action,” added Tanase.
“This may be contributing to a silencing effect in Parliament around one of the defining policy challenges of the 21st century.”
* The surveying of sitting MPs took place during December 2024 and January 2025. The public polling benchmark was a nationally representative survey of 4,201 UK adults conducted by Ipsos UK between 18 and 24 April 2024. The polling asked people about the specific policies outlined in the study, such as the home insulation policy and green product tax.
** The study’s authors write that: "No significant silencing effect was found for the energy efficiency subsidy policy, likely due to the broader expected popularity and relative lack of controversy of subsidy policies compared to tax-based measures."
The sample of MPs in the study consisted of sitting Labour (80), Conservative (16) and Liberal Democrat (4) parliamentarians. While it approaches representing the current composition of the Commons, there is an overrepresentation of Labour MPs and an underrepresentation of Liberal Democrat MPs.
