The SPS secured 0.96% in December 2's widely-criticized parliamentary polls, which saw an overwhelming victory for the pro-Kremlin United Russia party.
Barring major political and social developments in Russia, Nemtsov has no realistic chance of becoming the country's next president.
The leader of the SPS party said earlier on Monday that he was resigning over his liberal opposition party's crushing defeat at December's parliamentary elections.
"I bear full responsibility [for the defeat] and am stepping down," Nikita Belykh said at a party congress.
Belykh questioned the validity of the election results, but admitted that both he and the party had failed to "forge a united democratic front" ahead of the polls.
United Russia's nominee, First Deputy Prime Minister Dmitry Medvedev, enjoys President Vladimir Putin's backing, and is widely seen as the front runner in the polls. Indeed, some sections of the Russian media have already begun referring to Medvedev as "Russia's future president."
On Monday, the Kommersant daily quoted Soviet-era dissident and presidential candidate Vladimir Bukovsky as saying that he had signed a deal with ex-prime minister Mikhail Kasyanov and the SPS's Nemtsov to coordinate activities in the run-up to the elections.
According to Bukovsky, the three men will each attempt to collect the 2 million signatures required to support their applications to run in the presidential election. If successful, they will then undertake the next step - registration with the Central Election Commission.
However, in the event of more than one of them eventually gaining the right to run in the March 2 presidential elections, the one with the highest opinion poll rating will run as a sole opposition candidate.
