I would first caveat that no heat pump user should use a default electricity tariff. However, the energy price cap is illustrative about the general trends.
Compare July 2025 to July 2026:
Now, some of this are due to policy changes made by the government. However, given there's only 5% VAT on gas it is inherently the case that electricity has more room for manoeuvre. Electricity has tons of added policy costs which could be shifted without too much unintended consequences.
Combined together this means that the heat-pump user will be experiencing far more consistent heating costs over this period of crisis than the gas boiler user. For those who want sustainable bills which fluctuate less during crises the choice should be obvious.
How to educate the public about the need to innovate to reduce price volatility is a hard problem but these data certainly helps.