Graduates in technical and engineering subjects would be given £10,000 to join the armed forces, under plans unveiled by the Liberal Democrats to tackle recruitment problems.
The Lib Dems also pledged to keep defence spending at the Nato benchmark of 2% of national income.
Leader Tim Farron said he believed in a “credible” armed forces.
Labour and the Conservatives have both pledged to stick to the 2% Nato spending target.
The Lib Dems have also promised a new “careers for heroes” scheme to pay for the full cost of further and higher education for armed forces personnel who had served for 12 or more years.
“A recent independent report was a damning indictment of armed forces recruitment and retention, with some units facing 14% shortfalls in manpower,” said Mr Farron.
“Our Army, Navy and Airforce deserve the best and the brightest serving in them, and we must not stand by as those who have served face disadvantages.”
On Sunday’s Andrew Marr Show Defence Secretary Michael Fallon said the government could not force people to join the Army.
“We don’t have conscription in this country, the Army has to compete with other sectors in the economy,” he said.
The Conservatives have broken their 2015 pledge to not let the size of the army fall below 82,000 – it currently stands at 78,500.