In a concerning development, several soldiers were hospitalized with hearing impairments and headaches after testing new British Army tanks, just weeks before the tanks received deployment approval.

The long-delayed Ajax vehicles were officially cleared for deployment on Wednesday, marking a milestone eight years behind schedule.

However, the Army faced fresh embarrassment today as it was revealed that a safety investigation was launched after troops involved in summer testing reported injuries related to ‘noise and vibration.’

Approximately ten soldiers expressed concerns following a training session on Salisbury Plain, citing severe headaches, balance issues, motion sickness, and tinnitus.

Despite these alarming reports, an Army investigation concluded there were ‘no systemic issues,’ allowing the tank deployment to proceed as planned.

These injuries surfaced six years after similar problems were first linked to the tanks, issues that were believed to have been resolved.

The disaster-laden Ajax vehicles were finally declared ready for deployment on Wednesday, eight years later than planned

In December 2021, it emerged the tanks shook so violently that 310 people who had tested Ajax needed to have hearing assessments, while 17 were undergoing specialist treatment for hearing loss. Some were forced to leave the army and paid compensation.

On a visit to the Ajax factory at Merthyr Tydfil in South Wales, defence procurement minister Luke Pollard said these issues were ‘firmly in the past’.

He did not disclose that there had been noise issues as recently as the summer.

Asked how many soldiers still had hearing problems, he said: ‘I can’t give out numbers of people affected, because that can compromise medical data.’

‘But what we can say is those issues are firmly in the past. We would not be putting it in the hands of our Armed Forces if it were not safe. And I’ve been reassured from the top of the Army down to the folks that work on the platform that it is safe, and those lessons have been learnt.’

He insisted Ajax tanks – which cost £10million each and are designed to find the enemy from five miles away – are ‘the most advanced armoured fighting vehicles in the world’.

Defence procurement minister Luke Pollard said issues with the vehicles were ‘firmly in the past’

Britain purchased 589 of the vehicles for £5.5billion, with the total programme – including training – set to cost around £6.3billion.

A former Army officer who worked on the Ajax programme told The Times: ‘I think that vehicle can and will cause harm.’

They said there had been ‘ample opportunity to stop and do something else which, in light of Ukraine and other events, would seem a better use of £5billion’.

Some of the troops injured in the summer were sent to a military medical centre, understood to be within a hospital, for checks and observation.

There are six variants of the vehicle – all of which were involved in the tests.

However, it is understood the investigation into hearing problems is related to the Ajax, troop-carrying Ares, and the Athena – which functions as a mobile headquarters.

The noise problems are thought to be linked to headsets used on the vehicle, which have an inner earpiece and an outer piece.

When the programme began in 2010, the vehicle was set to enter service around 2017. Only 50 are now ready to be deployed.

It comes amid claims that defence chiefs ignored warnings over the safety of Sea King helicopters which have caused pilots and crew to develop rare cancers.

The Ministry of Defence said: ‘Safety of our personnel is a top priority. Ajax has been through rigorous trials and an assured safety process, and the evidence shows it is safe to operate.

‘Where concerns were raised over the summer, these were investigated by a safety team and no systemic issues were found. All armoured vehicles produce noise and vibration. We continue to ensure these do not exceed statutory limits.’