Zimbabweans have taken to the streets of Harare for the second time in under a year. In November they had cheered Robert Mugabe’s downfall after decades of misrule. But on Wednesday, hundreds clashed with police firing tear gas and soldiers using live ammunition as they protested that the presidential election was being stolen by the man who replaced him, Emmerson Mnangagwa. The ruling Zanu-PF party has already won a parliamentary majority, according to the official results. But the real prize is still to come and the opposition MDC Alliance has said the election of its 40-year-old leader Nelson Chamisa, successor to the late Morgan Tsvangirai, is almost assured.

The celebrations of Mr Mugabe’s downfall are long past, and were somewhat bittersweet even at the time. No one believed that the worst of Zanu-PF’s rule could be blamed on the president alone, and Mr Mnangagwa was nicknamed “the crocodile” because of his fearsome reputation as Mr Mugabe’s enforcer. But his promise to modernise the country, stabilise and revive its shattered economy and rein in at least some of the corrupt excesses won him cautious support at home and abroad.

Britain, as the former colonial power, has a particular duty to Zimbabwe. Boris Johnson, then foreign secretary, stressed his keenness to bring it back into the Commonwealth. Britain’s ambassador said that a free and fair election would be the key to unlocking the re-engagement of international institutions, debt restructuring and infrastructure investment too. The country is in dire need of a bailout, and offering an incentive to give its citizens a better deal makes sense. But the fear was always that the eagerness for good news would mean the bar would be set too low.

The campaign was undoubtedly an improvement on earlier contests, notably the deadly violence of 2008. Other parties held rallies, and Mr Mnangagwa responded calmly to a bomb attack at one of his events. Election day itself was peaceful. But state media remains skewed towards Zanu-PF. There were warnings of “ghost voters” on the electoral roll. Hopes of tabulating results independently have reportedly been dashed by the failure of many polling stations to post results outside, as they should. It is hard to see the electoral commission as impartial. Many complaints – such as misuse of state resources, instances of intimidation, and bias by traditional leaders – have now been backed by independent electoral observers. The head of the EU mission noted that ballots for the presidential vote were counted first. “I have yet to learn why they will be released last,” he said pointedly.

Not being Mr Mugabe is undoubtedly a point in Mr Mnangagwa’s favour. But it is not in itself a case for his leadership, or for welcoming Zimbabwe back into the fold. He and his party must be judged by a very simple standard: that the will of the people, expressed on Monday, is accurately and honestly tallied and respected. Anything less should bar them from that international welcome.