The voting does not start until Sunday morning, but the results are already in, according to Crimea's de facto leader, who said on Friday he was "absolutely certain" the region would vote to join the Russian Federation.

Crimea's controversial referendum has been organised in a matter of days, takes place with the Russian army occupying a number of key positions in the region, and will not be recognised by most of the world.

But there is an increasing sense of certainty here that not only will the required vote be delivered but that Moscow will oblige and welcome the Ukrainian peninsula as Russian territory.

Crimea's de facto prime minister, Sergei Aksyonov, said day he expected a turnout of 80% for the referendum, and a percentage even higher than that to vote for union with Russia. Recognition from Russia and acceptance into the fold should come next week, he said.

The ballots will ask voters to tick one of two boxes: option one provides for Crimea to enter the Russian Federation, while option two returns the region to the 1992 constitution, giving it broad autonomy within the Ukrainian state. Retaining the status quo is not an option.

Across Simferopol, billboards call on voters to make the right choice and choose union with Russia, and flags painted with a heart in the colours of the Russian tricolour flutter above roads. There is no campaigning for the other option on the ballot paper. Aksyonov said on Friday that the government would have welcomed anyone who wanted to campaign for remaining inside Ukraine, but such forces did not exist.

There are those who dissent, mainly among the ethnic Ukrainians and Crimean Tatars who together make up around a third of the population. In Simferopol on Friday there were several isolated protests, each involving a hundred or more Tatars, who waved Ukrainian flags, and shouted "Crimea is Ukraine".

At one of the protests, a pair of cheerful middle-aged Tatar women carried a banner that read "Putin is a fascist".

"He is the aggressor, he has started this aggression," said one of them, Nuriye. "Russia has constantly been the aggressor in our land, starting from Catherine the Great to the present day. We've been fighting ever since and we will fight if they attack us again. We want to be part of Ukraine."

While there is widespread support for closer ties with Russia, the referendum is taking place in an information blackout after the local authorities earlier in the week cut off all Ukrainian television stations and replaced them with Russian ones (inside Ukraine, a similar move was made to cut off Russian channels). The mood towards Western journalists and the west in general is hostile, partly due to an aggressive campaign by Russian and local channels.

One local channel reported earlier in the week that the BBC had brought people painted red to Sevastopol in order to film them and claim that they had been beaten up by nefarious Russians and Cossacks. There is a general assumption that the west has taken an unfair stance on Crimea, further fuelled by such reports.

"Why is it that you in the west say you support self-determination but you are against us being part of Russia?" said Tagir Asainov, a Crimean Tatar who nevertheless supports union with Russia. "This is Russia, it has always been Russia, and the vast majority of people here want to be with Russia. All that is happening is that a historical injustice is being rectified, and instead of celebration we are getting criticism from the west."

Across the peninsula, groups of armed men are getting ready to defend the results of the referendum. Vladimir Putin has claimed, implausibly, that the well-organised troops in unmarked green uniforms are not Russian soldiers but Crimean self-defence units. But in addition to the Russian troops, there are also genuine volunteer brigades of locals, keen to defend the Crimean peninsula against what they claim is a far-right "fascist" threat from the new Kiev government.

In Simferopol's main square on Friday, new recruits to the militia brigades were receiving orders, some of them in rag-tag military fatigues, others in plain clothes but marching in step. These groupings have sprung up across Crimea, sometimes acting in concert with the Russian army and at other times independently. At the headquarters of the local pro-Russia militia in the town of Bakhchisarai, 39-year-old Ivan knocked back shots of brandy. Two large Russian flags covered the wall and Kalashnikovs were propped in the corner.

"So, we are already in Russia. Everybody knows that. It has already been decided," he said. "This is a celebration. This, everything you see around you, this is a historical justice.

"All the population here was Russian, it was only Khrushchev who gave Crimea to Ukraine. We do not like that we were given as a gift like a box of chocolates. Russians are our brothers, and we just want to join to our brothers."

Although the referendum is not until Sunday, the real energy in Crimea is already being put into how the peninsula will look after the expected union with Russia. Local parliamentarians have said that oil and gas resources in the Black Sea have already been taken under control and will be passed to the Russian state energy concern, Gazprom. The rouble is expected to be introduced in the coming months. Aksyonov said on Friday he expects a formal decision on union to come from Russia within a week and the transition process to take up to a year.

"We have specialists from various Russian ministries in Crimea at the moment working with us on how to integrate," he said.

In the lime-green corridors of the Taurida University in Simferopol, the 18,000 students started their studies working towards a Ukrainian degree and will probably finish them with a Russian qualification.

For the professors, it will mean a lot more money. The starting salary for a professor at a leading Russian university is three times higher than in Ukraine. Many of the students are also excited about joining Russia, but the mood is far from unanimous.

"Crimea is different from Ukraine, we need autonomy, and we need our rights respected," said Dmitry, an engineering student. "But I have the feeling something terrible is happening. There has been a coup and an invasion, and it has all been manipulated as a popular uprising. I am not sure it will end well."

Harriet Salem contributed reporting from Bakhchisarai