Members of the University and College Union and Unison branches voted in favour of a strike, with a joint stoppage now scheduled for 4 October.
The coordinated action means that both academic and support staff will be on strike.
Both unions said that 80 per cent of members who participated in the ballots voted for strike action. Unison said its vote was on a 40 per cent turnout and the UCU said its turnout was 51 per cent.
The unions say the university is planning for up to 300 redundancies, which Unison claims would amount to 15 per cent of the total workforce.
Middlesex will charge one of the highest undergraduate tuition fees in the UK in 2012 (with £8,602 as the average fee after financial support is taken into account).
Arthur Husk, UCU branch chair, said: “It is a shame that things have had to come to this but the university’s cost-cutting measures will have a devastating impact on academic provision, the student experience and staff morale.
“We still want to avoid any disruption, but the vice-chancellor needs to get round the table with us and genuinely look at ways to resolve the dispute.”
Paul Howell, Unison branch secretary, said: “Staff are already feeling the strain of being overburdened with work, effectively being told to do the work of two. The consequences to the university and students could be dire. Something will inevitably give.”
A Middlesex spokesman said the strike action was “both disappointing and surprising”. He added that the university was working with the unions and applications were still being considered for voluntary redundancy, with the aim of ensuring “that if compulsory redundancies are needed, these are kept to an absolute minimum”.
The spokesman said all universities “are facing unprecedented government cuts and while we regret that these measures are required, we must take prompt action to ensure Middlesex University remains in a strong and sustainable financial position in the years to come”.