If Labour wins next week’s general election, a Jeremy Corbyn government would come under immediate assault from the political establishment, the secret state and the financial markets to name just a few enemies of the people. We need to plan the resistance now.

Corbyn’s manifesto may not overtly challenge capitalism – in fact the word doesn’t figure in the text – but radical policies on health, education, social care, infrastructure and foreign policy go against the grain of recent decades.

The Blair and Brown governments cut corporation tax and borrowed against expected future revenues; Cameron and Osborne imposed austerity – and cut taxes for business and high wage earners.

New Labour and the Tories made outsourcing and markets a mantra. Corbyn is proposing to do the opposite and bring privatised NHS services back into the public domain, for example.

Blair and Cameron were gung-ho supporters of US-led military intervention and drone killings. Corbyn says he wants neither.

Whereas the Tories see austerity continuing indefinitely, Corbyn and shadow chancellor John McDonnell want to bring it to an early end.

A Corbyn government would be prepared to tax and spend more to pay for its programme.

Whereas Theresa May is ready to “take on Europe” in Brexit negotiations on behalf of big business, Corbyn is sounding more conciliatory and will put the protection of workers’ rights top of his agenda.

All this is anathema to an establishment driven by its embrace of corporate and military power. They will strike back, as surely as night follows day.

Demonstrations and protests will no doubt be organised in the event of a concerted backlash against a Corbyn government. But we will need to do more because what’s at stake is who has the real power in the UK.

The elected government of the day is only the public expression of power. Behind the scenes are state institutions that have grown up alongside capitalism, encouraging its development and its grip on economic affairs.

These include the powerful departments of state, led by the Treasury, like the Ministry of Defence, and includes the Bank of England and other bodies not directly within Whitehall. Added to them are defenders of the status quo like the spy agencies MI5 and MI6,  Special Branch and other deep state bodies such as GCHQ.

All these bodies are dedicated to upholding private property in the shape of capitalist forms of ownership and control – by force when and where necessary. They have formed a matrix of working relationships with corporations and financial institutions, who drive policy making at state level.

This is what Corbyn and McDonnell will be up against. So no apologies for returning to Labour’s support for a convention on the constitution, where the manifesto says:

We will consult on its form and terms of reference and invite recommendations on extending democracy. This is about where power and sovereignty lies – in politics, the economy, the justice system, and in our communities. The Convention will look at extending democracy locally, regionally and nationally, considering the option of a more federalised country.

Getting this going would need to be a priority. Why not invite people to volunteer for a convention or conventions (they could be organised regionally, for example) and ensure that they are a reflection of diverse communities and the different countries within the UK?

The convention(s) could devise their own agenda, seeking expert advice where necessary and be given the support of a secretariat. Members could be given time off from work and paid while they deliberate. If there are several conventions, they could come together to make final recommendations.

Identifying where power lies would hopefully lead to recommendations about extending democracy into areas like the workplace, for example, where none exists at present, and reshaping our failing political system.

In other words, a blueprint for real democracy would emerge. With the present state hostile to this idea, a convention on the constitution could also become a starting point for a democratic revolution that transfers power to the 99%.