Four candidates will take part in presidential elections on March 2: Medvedev, Zhirinovsky, Communist leader Gennady Zyuganov, and Andrei Bogdanov, the leader of the tiny pro-Western Democratic Party.
Medvedev, Russia's first deputy prime minister, who was publicly backed by Putin as his successor in mid-December, has so far received 181 million rubles ($7.4 million) for his election campaign, but has spent less than 8 million rubles ($326,000).
The ultra-nationalist Liberal Democratic Party leader Vladimir Zhirinovsky has received a total of 140 million rubles ($5.7 million) in campaign funds and has spent 48 million rubles ($2 million).
Communist leader Zyuganov has raised 39 million rubles ($1.6 million) spending 30 million ($1.2 million).
The Democratic Party leader, Bogdanov, received just 4.8 million rubles ($195,000), and has already spent 4.3 million ($175,000).