Ambulance arrivals at the Royal Surrey County Hospital A&E were below average on January 11 – the day ambulance workers went on strike across the country – new figures suggest.

Around 25,000 ambulance workers from the Unison and GMB trade unions went on strike on Wednesday, January 11 last week, with staggered walkouts staged across England and Wales.

Every ambulance region other than the East of England was affected by the strikes.

The latest NHS England data suggests the number of ambulances arriving at A&E departments across England on January 11 was 26% below the average across the other weekdays last week.

At Royal Surrey County Hospital NHS Foundation Trust, 33 ambulances arrived at A&E on January 11 – below the average of 40.

The average across weekdays excluding Wednesday was used to minimise the impact of the daily fluctuations and difference in demand at the weekend.

Nationally, ambulance handover delays improved on January 11, with 6% of arrivals waiting longer than an hour, compared to 9% across the rest of the week.

Rachel Harrison, national secretary at the GMB, said: "This Government has left our NHS so broken that performance actually improved on strike day.

"Instead of praising them, this Government has demonised them and pushed through a fresh attack on workers' rights.

"They are scaremongering and playing political games – they need to talk pay now."

The GMB has since announced ambulance staff will strike on four more dates – February 6, which coincides with a nurse's strike announced by the Royal College of Nursing, February 20, and March 6 and 20.

Unite has also announced a further 10 strike dates over the coming weeks, affecting services in several regions of the country.

The unions are asking for a pay rise above inflation, but the Government has offered an average NHS pay rise of 4.75% – well below current inflation.

The NHS England figures also show ambulance delays are improving, with a total of 23% of ambulance patients in England waiting at least 30 minutes last week to be handed to A&Es – down from 36% the previous week and the lowest level so far this winter.

Some 9% of patients waited more than an hour to be handed over – also the lowest proportion this winter.

Of the 271 ambulance arrivals at the Royal Surrey County Hospital in the week to January 15, 6% were delayed by at least 30 minutes – down from 17% the week before.

Health and Social Care Secretary Steve Barclay said: "It is welcome to see improvements in urgent and emergency care performance in the latest data

"There is still considerable work to do, but we continue to support health and care services throughout this difficult period as well as engaging constructively with unions to find a resolution to ongoing strike action.

"Last week, I announced up to £250 million of funding to immediately reduce hospital bed occupancy, alleviate pressures on A&E and unlock delays in handing patients over from ambulances."