Unidos Podemos registers no-confidence motion against PP and Rajoy to be debated in two weeks' time

The motion is expected to be debated in Parliament at the end of this month or the beginning of next.

With the right-wing governing party – which is in a minority, although has the most Parliamentary seats out of all those who gained votes in the last election – blighted by a string of corruption scandals dating from the 1990s almost to the present day, and several hundred PP politicians at all levels either in custody or under investigation, Unidos Podemos says its no-confidence motion 'sends out a clear message' that 'there is hope' for the nation 'despite the PP's pillaging'.

Court cases are investigating tens of millions of euros going astray, either through inflated invoices, grants not spent in full on their purpose, or tax evasion and, although as yet very few have been formally convicted due to the slow process of the wheels of justice, strong indications of malfeasance means the picture looks bleak for a significant number of PP members and private-sector company bosses they have been linked to.

The motion has been signed by all Podemos factions including the Catalunya-based En Comú Podem ('In Common We Can') and En Marea, from Galicia.

If it were to prosper, Podemos' leader Pablo Iglesias would be the alternative candidate.

But it does not seem likely it will go through, since many opposition politicians – even though they do not consider the PP suitable to run the country – would not back Iglesias as a leader and believe the motion is merely a tool to increase his personal status and power.

Podemos is the third-largest political force in Parliament and in power in the country's largest two cities, Madrid – under Ahora Madrid, led by ex-judge Manuela Carmena – and Barcelona.

The socialists, or PSOE, are the second-largest and, historically, the PP's main rivals, but their leadership crisis means if a snap election were to be called today, they would not be a viable opposition.

Whilst candidate for heading up the PSOE, former leader Pedro Sánchez has tentatively suggested a no-confidence vote to oust the president would not be a bad idea, his view is not shared by his rivals for socialist boss, Susana Díaz – currently regional president in Andalucía – and Basque leader Patxi López.

And Sánchez's policy views do not always mix with those of Podemos – attempts to form a government between them last year following the first of two inconclusive general elections revealed a deep divide over the Catalunya referendum issue, and now, Sánchez says he would outlaw surrogacy if he had the choice, barring future parenthood to all-male couples and to women who cannot carry their own child.

Centre-right Ciudadanos, Spain's fourth-largest political force, has also outright rejected the no-confidence motion, and as yet Unidos Podemos has been unable to meet with the Basque Nationalist Party (PNV) to gain their views – although these are expected to match those of the PSOE and Ciudadanos.

Unidos Podemos hopes that at the very least, the motion will drum up public support against the PP – but in each of three general elections between December 2015 and November 2016, the PP gained the largest amount of votes.

However, among the other corruption investigations under way, one of these involves digging into how the PP funded its electoral campaign amid suspicions of foul play.

Photograph: Unidos Podemos on Twitter