Myanmar opposition leader Aung San Suu Kyi has announced that she will form an alliance with Shwe Mann, the ousted chairman of the governing Union Solidarity and Development Party.
She was speaking as parliament reopened on Tuesday for its last session before November's national elections.
Last week Shwe Mann was dramatically removed from his position.
His dismissal was seen as an emphatic move by President Thein Sein to tighten his political grip ahead of the vote.
Speaking while MPs gathered in the capital Nay Pyi Taw for a final round of parliamentary meetings before the 8 November vote, Suu Kyi said that Shwe Mann's dismissal by the president on Wednesday made it clear "who is the enemy and who is the ally".
She said that her National League for Democracy (NLD) party would work with the "ally".
The Nobel laureate joined the US and Britain in expressing concern over the removal of Shwe Mann before the elections, which are the first since democratic reforms began in 2011.
"This is not what you expect in a working democracy," she said in relation to the circumstances of Shwe Mann's removal, adding that divisions within the USDP were likely to result in increased electoral support for the NLD.
Correspondents say that the alliance between Suu Kyi and Shwe Mann is significant because he has retained his influential role as parliamentary speaker, and has been widely seen as a possible compromise presidential candidate.
Suu Kyi herself cannot run for the post under the terms of the constitution drafted by the military government.
She has not detailed how her alliance with Shwe Mann will work, but one likely area of collaboration might be amendment of the constitution to allow her to run for the presidency.
The government for its part on Tuesday has tried to downplay Shwe Mann's removal, which it described as "part of a normal course of business" for a political party.