A handful of campaigners from the Stop the War group held a rally in Guildhall Square following the departure of the 65,000-tonne warship on Saturday night.
The £3.2bn aircraft carrier will be spearheading the UK’s carrier strike group on a 28-week mission to the Far East and back.
It’s embarked airwing of 18 F-35B stealth jets will also be called into action, with airstrikes planned against terrorists from the so-called Islamic State in both Iraq and Syria.
But campaigners from Stop the War have questioned the purpose of the ship and fear its deployment could provoke more needless conflict.
That comes in spite of messages from the First Sea Lord, Admiral Tony Radakin who insisted on Saturday that the task group’s deployment was ‘non-confrontational’ and with the aim to ‘promote the UK’s post-Brexit trade agenda’.
Richard Spence, organiser of the protest in Portsmouth said: ‘These aircraft carriers have been referred to multiple times as the physical embodiment of global Britain as part of our new foreign policy approach to the rest of the world after having left the European Union.
‘This strategy includes things like increasing the military budget by billions of pounds, increasing the amount of nuclear warheads by 40 per cent, deepening our relationship with authoritarian countries including the gulf dictatorships and Israel.
‘We think it’s necessary to be here to let the rest of the public know that we oppose this considering in the last 20 years the war on terror has seen hundreds of thousands of people die. War is a choice which we initiated.
‘We feel Britain should be a normal country and put our resources into real human needs. These aircraft carriers cost £6.4bn combined – that’s enough to pay for 100,000 council homes which we desperately need.’
Nine ships, 32 aircraft, and 3,700 military personnel are involved in the UK’s carrier strike mission.
Defence secretary Ben Wallace said the effort would ‘write Britain’s name in the next chapter of history - a truly global Britain that steps forward to tackle the challenges of tomorrow, working hand-in-hand with our friends to defend our shared values and uphold the rules-based international order.’
‘This deployment shows that we are strong on our own, but we are stronger with our allies,’ he added.