To fully understand the euphoria that greeted the news on Tuesday night that Robert Mugabe had finally resigned as president of Zimbabwe, consider the case of Mathanda Mbo-Dube. A few years ago, Mbo-Dube was enjoying a drink with friends when Mugabe, then 88, appeared on a TV screen in a sports bar near Bulawayo. Mbo-Dube commented that the president was “too old”. Overheard by members of Mugabe’s secret police, Mbo-Dube was arrested and jailed for the crime of “undermining and insulting the president”.

Mugabe’s removal after nearly 40 years is currently uniting all shades of opinion in celebration. But what will it take to move the country forward now, after decades of crisis?

The British foreign secretary, Boris Johnson, the Africa minister, Rory Stewart, and others in the EU have already spoken in favour of free and fair elections as soon as possible. They are wrong.

True, credible elections are ultimately the best way to take Zimbabwe to a democratic future. But there is nevertheless no way of ensuring that a ballot can be meaningful within the short period between Mugabe’s removal and the scheduled date for elections, in June next year.

The apparatus of vote-rigging and repression that Mugabe entrenched over the years cannot be undone in a year or two, maybe not even in three. The generals whose soft coup kickstarted the process of Mugabe’s demise were the main architects and enforcers of this machinery. They did not initiate Mugabe’s toppling because they have suddenly become genuine democrats. They embarked on their actions because they had no other choice.

The first lady, Grace Mugabe, had put them on notice as she set to clear her path to the presidency, going as far as accusing the army of plotting to kill her son. So the generals had to save their own skins by clearing the path to power for their ally Emmerson Mnangagwa. He is their best insurance against any future repercussions over past crimes. They will want to keep him in power for as long as possible using the very machinery they used to prop up Mugabe. To think they will allow free and fair elections – or let Mnangagwa do so – is fanciful.

Removing Mugabe, by whatever means, was always going to be the first step towards resolving the Zimbabwe crisis. But there is no incentive for the generals or Mugabe’s Zanu-PF party to swiftly dismantle a system they created, and which they now desperately need to keep their man in power.

If next year’s elections proceed, they will be under the very same conditions that benefited Mugabe and ruined the opposition. This is not to say that Mnangagwa will, initially, be worse than Mugabe. He is certainly a better pragmatist, aware he needs to demonstrate at least cosmetic reforms to international donors and investors. But the polls will be a walkover for Zanu-PF.

Central to the party’s rigging machinery has been a defective electoral roll comprising millions of ghost voters to which the opposition is routinely denied access. Attempts by the stuffed Zimbabwe Electoral Commission (ZEC) to introduce a biometric voter registration (BVR) process to create a new roll are so far fraught, with some NGOs reporting intimidation (pdf). On a recent visit to Zimbabwe I struggled to locate a BVR centre to re-register as a voter. When I found one, I stood behind 22 people in a queue. With officials taking at least 50 to 60 minutes to process each applicant, I gave up, as did many behind me. But in Zanu-PF’s rural strongholds, BVR centres are strategically located at every corner. As things stand, there is simply no way of registering a significant portion of opposition voters in the urban strongholds before the closure of the BVR process in January 2018.

Can the system’s bias be made fairer just because Mugabe is gone, replaced by the man who masterminded the fallen leader’s institutions? I doubt it. Certainly not in the short term.

What Zimbabwe needs instead is a period of healing and recovery through a transitional authority, with Mnangagwa at the helm but incorporating other opposition voices and activists – particularly Morgan Tsvangirai, Dumiso Dabengwa, Joice Mujuru, Welshman Ncube, Nkosana Moyo and Tendai Biti. A transitional authority should remain in place for three years, prioritising reforms and economic recovery. It may even make it easier to mobilise the quick aid needed to restore basic services.

In Chitungwiza, a densely populated area where my father lives, south-east of Harare, not a drop of water has flowed from municipal taps for eight years. The people are saved by boreholes sunk by Unicef. The municipality has no money to buy water treatment chemicals and repair broken infrastructure.

Zimbabweans joke that you go to the country’s dilapidated state hospitals and clinics to die, not to be saved. Infrastructure across the country is entirely run down and the economy is reduced to the levels of the 1960s. Pushing such a traumatised people into early elections would be unhelpful.

More worryingly, the Zimbabwean diaspora remains completely excluded from the electoral process because Mugabe had long suspected Zimbabweans in exile of being opposition supporters. The critical broadcast media sector, in which independent players have been completely excluded for years, would equally need a massive overhaul.

The shortcomings of Zimbabwe’s electoral system are bad enough. Moreover, the army generals responsible for Mnangagwa’s rise have not yet recanted their vow never to let anyone who did not participate in the 1970s liberation struggle rule Zimbabwe. Unless this changes, their stance also automatically disqualifies Tsvangirai, the only opposition leader to have defeated Mugabe in elections . The generals repeatedly refused to salute him after he was co-opted into a unity government as prime minister in the wake of his MDC’s victory in 2008 elections. Will there now be a change of heart by the generals? Again, I doubt it.

Fortunately, the war veterans have declared that no single party can feasibly shoulder the responsibility of rebuilding Zimbabwe, and they support the idea of a transitional authority.

The opposition stands a better chance of influencing positive electoral reforms in such an arrangement, and Britain and the EU should support it by making future aid to Zimbabwe conditional on its formation. Hurried elections will only perpetuate Zanu-PF hegemony.

Having left Zimbabwe in 2002 as Mugabe’s intimidation of the independent media reached a high point, I am as elated as any Zimbabwean at his demise. However, it would be naive to believe Mnangagwa’s ascendancy marks the dawn of a new era, without the necessary pressures the world can exert to ensure that he breaks completely with the past.

• Basildon Peta is a Zimbabwean journalist and activist, and a former member of the general council of the Zimbabwe Congress of Trade Unions