Three in four people hoping to join the army withdraw their application before serving thanks to being stuck on lengthy waiting lists.
And more than 100,000 since 2014 have waited six months for a response before giving up.
The alarming new data comes amid a recruitment crisis in the armed forces and adds to growing concerns that the number of personnel could drop below the target force of 73,000 within months.
Last year alone, almost 74,000 people who applied to join the army, RAF or navy withdrew, amounting to more than half of the potential recruits.
This was particularly stark in the army with seven in ten applicants giving up on the process altogether before getting accepted.
Three in four people hoping to join the army withdraw their application before serving thanks to being stuck on lengthy waiting lists. And more than 100,000 since 2014 have waited six months for a response before giving up (Stock Photo)
More than 8,400 of the 54,128 who pulled out of joining the army before even serving last year waited at least six months before they withdrew, The Times reports.
But the problem was seen across all three sectors of the armed forces with fewer than ten per cent of the 137,000 people who applied to join last year actually serving, according to the fresh figures uncovered by shadow defence secretary John Healey.
Some 1.1 million young people have applied to join the armed forces in the last ten years but more than 800,000 have withdrawn.
This has resulted in the Ministry of Defence recruiting around 132,000 people and turning down some 170,000 hopefuls.
Britain, along with countries such as the US, France, Germany and , is struggling to maintain healthy numbers in the armed forces with the pull of lucrative private sector jobs causing many to leave.
Mr Healey said that the British Army was currently at its smallest since it was fending off Napoleon in the early 19th century.
He said: ‘Hundreds of thousands of people willing to serve and defend their country have simply given up on their ambitions, while ministers have failed to get to grips with the problems.
‘The Conservatives have presided over 14 years of failure in defence — missing their recruitment targets every year.’
Defence secretary Grant Shapps branded the recruitment system ‘ludicrous’ and said that the current ‘Amazon’ generation would not wait months to get into the army as it was used to getting everything instantly.
He added that various medical rules, including health of family members, caused applicants to be rejected.
A Whitehall source said that the defence secretary was attempting to fix the recruitment process and address the difficulties faced in retaining troops.
Capita Public Service, which oversees army recruitment, faces a fine every time it loses an applicant and is aiming to digitise medical records to tackle the current lengthy health checks.
Army sources claimed that the average time between expressing interest and commencing training was 5.3 months.
Tim Ambler, a senior fellow at the Adam Smith Institute, said the department was ‘incompetent’, adding: ‘In an age where young people do not really want to work, they have to be wooed.’
Defence secretary Grant Shapps (pictured) branded the recruitment system ‘ludicrous’ and said that the current ‘Amazon’ generation would not wait months to get into the army as it was used to getting everything instantly
Capita chief executive Richard Holroyd said the firm was trying to speed up the process and cited the number of Commonwealth applications as an obstacle.
A Ministry of Defence spokeswoman said: ‘Recruitment and retention are absolute priorities and we have introduced a range of measures to respond to the current recruitment challenge, which is affecting many other militaries across the world.
‘While it does take time to recruit the right people to the military, we have sped up army recruitment by 9 per cent in the last year, reducing the average time it takes for a regular soldier to join to less than 140 days.’