The shadow defence secretary has told the BFBS Sitrep podcast that billions of extra pounds granted for defence is "welcome" but he fears the investment is "without a strategy".
John Healey MP said last week's announcement of a £16.5bn boost to the Ministry of Defence's (MOD) budget over the next four years "promises an overdue upgrade of Britain’s military after a decade of decline".
However, Mr Healey added: "The challenge now is with the MOD to do what it does generally very badly, which is delivery, delivery, delivery."
He said it is important to "avoid the mistakes" seen after 2015, namely a £13m "black hole" in the equipment budget.
The spending increase is on top of a promised 0.5% annual increase in real terms.
According to Number 10, the boost is expected to cement the UK's position as the largest defence spender in Europe and the second-largest in NATO.
The Government has called on military chiefs to advise them on how the extra defence investment should be spent.
Mr Healey said it is necessary to recognise that "highly trained forces are absolutely indispensable".
He said: "I want to see, as part of this Integrated Review, when we get this review, avoid the mistake of the last two and give proper priority to personnel who’ve got to be at the heart of it.
"As we move much rightly to much higher-tech systems into the domains of cyber and space and unmanned weaponry and systems, we’ve got to remember that at the heart there’ve got to our full-time, highly-trained troops."
Last week, Defence Secretary Ben Wallace said the spending boost was "excellent news for defence", adding it "provides us with the financial certainty we need to modernise, plan for the future and adapt to the threats we face".
WATCH: Boris Johnson announced the defence spending boost last week.
"Next year represents a huge opportunity for this country, and defence will be at the forefront of creating the jobs and business opportunities that will help us build back from the pandemic," Mr Wallace said.
Earlier in the week, Chancellor Rishi Sunak presented a one-year Spending Review to the House of Commons, which features a pause in pay rises for public sector staff outside of the NHS.
This move will see some British military personnel affected by the pay freeze in the next financial year.
Speaking on the Chancellor’s announcement, Mr Healey said he believes it will "demoralise a lot of people" that have helped during the coronavirus pandemic.
"I think this is a huge disappointment that the Government when it feels it needs to find some savings, comes first for public service workers including the Armed Forces,” he told Forces News.
The pay freeze announced by the Chancellor will see workers who earn more than £24,000-a-year affected, with those whose annual salaries are below that amount "guaranteed" a wage increase.
It is understood around 1.5 million people will be affected by the freeze.
"To protect jobs, pay rises in the rest of the public sector will be paused next year," Mr Sunak said.
"The 2.1 million public sector workers who earn below the median wage of £24,000 will be guaranteed a pay rise of at least £250."
It means the majority of Armed Forces recruits and junior ranks are likely to get pay rises next year.
In 2019/20, under half of military personnel received incremental pay progression, separate to the Armed Forces Pay Award.
Pay progression, as well as overtime, performance pay, and salary increases relating to promotions, are exempt from the pay freeze.