Completing his journey across Russia aboard the Trans-Siberian railway before Sunday's presidential election, Al Jazeera's Jonah Hull arrives in the capital Moscow, where he finds emboldened opposition activists testing the limits of protest and debate.

Tens of thousands of young, middle class Russians took to the streets in protest over allegedly rigged parliamentary elections in December 2011 in a rare show of protest against the country's rulers.

"We were sitting and watching state TV, and at the same time seeing online videos of fraud at polling stations," says Olga Kuracheva, an activist.

"We were horrified. This sort of thing should not happen. We saw the call on Facebook for a protest and we realised we had to join it."

Like many activists Olga believes Vladimir Putin, the prime minister seeking to return to the Kremlin top job, is likely to win in the first round.

But the capital from which he will govern is alive with new and open debate that will challenge the way he runs things in future, our correspondent reports.

Source: Al Jazeera