As pro-European MEPs we grow weary of the government claiming credit for European achievements while blaming Brussels for its own inaction or mismanagement. The capping of credit card charges is a sterling example. We battled for this in the European parliament while our government tried to block the move in the European council. Once passed, and finding that customers rather liked the idea of lower bills, ministers claimed the credit, suggesting that “rip-off charges have no place in a modern Britain”.

Conversely, finger wagging at Brussels to deflect from British government failure is a well-rehearsed strategy. The latest blame game is about household solar batteries, which HMRC claims must be subject to the higher rate of VAT because of EU state aid rules. So let’s firmly hit the off switch on the misinformation being peddled on this issue and get to the truth of the matter.

HMRC pushes steep VAT increase for new solar-battery systems Read more

In January last year the EU commission published new proposals on VAT. A key aim of the revised rules was to close the loopholes that lead to large-scale VAT fraud. This costs the EU €50bn (£44.7bn) a year – that’s money that funds our schools, hospitals and more.

The proposed new rules also offer more flexibility for countries to set rates and to extend VAT exemptions – including a zero rate and some reduced rates – but the proposals are being blocked because there is still no unanimous agreement between EU countries. The UK has been one of the countries showing a reluctance to push for reforms that could provide the flexibility to reduce or zero-rate VAT for energy efficiency measures.

But the government also likes to point towards a 2015 European court of justice (ECJ) ruling, which concluded that the reduced 5% rate of VAT on the supply and installation of energy-saving materials was in breach of EU rules. However, the ECJ also ruled that a reduced rate could apply if it was “part of a social policy”.

As unhelpful as the ECJ ruling was, there are a number of ways that the British government could have engaged constructively with it.

First, it could have explored its breadth and almost certainly found that energy-saving materials used in home insulation do not include batteries.

Second, it could have changed domestic legislation to defend energy efficiency as social policy – which would allow the reduced rate as the ECJ ruled. It is undisputable that reducing energy costs for poor households is a social good. Doing so would reduce the annual scandal of cold-weather deaths.

Two-thirds of Britons agree planet is in a climate emergency Read more

Third, it could have influenced the current debate over the revision to the VAT regime and supported the Greens in demanding that all products that support the sustainability transition will be zero rated for VAT. But what can we expect of a government with totally different priorities? It continues to subsidise fossil fuels, backs fracking, wants to expand airports and build more roads, blocks onshore wind power and removes incentives for solar, and has continuously frozen the fuel tax escalator while it is forcing councils to cut subsidies to bus services and presides over the most expensive railway system in Europe.

Meanwhile, as a thoroughly pro-European party, we Greens want to see an EU-wide Green New Deal that will place a social agenda at the heart of the fight against the climate emergency. This offers the prospect of a triple win: new and better jobs, improved welfare and reduced carbon emissions.

It is hard to see how a Conservative government, gung-ho as it is for the hardest, most damaging version of Brexit, would ever engage constructively in the current debate in Europe over the revision of VAT rules. Far better for its Brexit narrative that the finger remains firmly pointed in the direction of Brussels.

Brexit is casting its damaging shadow over important political policies and priorities. VAT on solar batteries is just one example. The government decided first to ignore the EU rules it was signed up to, then pick a fight with Brussels, then over-interpret the result of a legal case and use it to undermine support for the EU among the green lobby. In this sense it is a perfect example of how our national politics under the Tories has become subjugated to Brexit posturing while urgent environmental and social priorities are ignored.

• Molly Scott Cato is Green MEP for South West England