SPAIN’s conservative government is facing a potential challenge to its rule as its Catalan crackdown sparks a backlash at home and abroad.

Key figures on the country’s left yesterday called for a bid to unseat the minority administration of Prime Minister Mariano Rajoy and allow an independence referendum in Catalonia.

Mr Rajoy’s Partido Popular or PP has thrown the full weight of the Spanish state behind blocking an unauthorised vote still scheduled to take place on Sunday.

Armed paramilitary police last week arrested some organisers of the plebiscite, which has been formally “suspended” by Spanish judges pending a drawn-out investigation in to its constitutional legality.

However, Mr Rajoy’s crackdown – described as “repression” by his Catalan critics – this weekend appeared close to uniting some of his divided opponents.

The leader of the anti-austerity party Podemos, Pablo Iglesias, yesterday led demands for Spain’s fractured left to unite to bring down Mr Rajoy.

Mr Iglesias urged the leader of Spain’s mainstream centre-left opposition, Pedro Sanchez of the Socialists, to lodge a motion of no confidence in Mr Rajoy.

Podemos, the Socialists and a scattering of smaller green, left and pro-independence parties could outnumber Mr Rajoy’s PP and the ultra-unionist group Ciudadanos in parliament. However, previous attempts to forge an alliance have failed.

Mr Iglesias, addressing the Socialist leader, said: “Comrade Sanchez, don’t fall in to the trap of a united front with the PP.

“We need a new democratic government of plurinational unity which will organise a referendum in Catalonia.”

Pablo Iglesias

HeraldScotland: Podemos (We Can) party leader Pablo Iglesias arrives for a news conference in Madrid, Spain, December 21, 2015. REUTERS/Andrea Comas. (50277831)

Podemos – and a related party called Podem in Catalonia – are not pro- independence but support what Catalans call the “right to decide”.

So does Ada Colau, the poverty campaigner turned mayor of Barcelona, who joined Mr Iglesias in his exhortations to Mr Sanchez.

Catalans are divided over independence but a clear majority want a vote to settle the matter.

A call by MSPs for a Scottish-style vote made headlines across Iberia yesterday, as previously did First Minister Nicola Sturgeon’s backing of a democratic solution.

There is no “No” campaign for the referendum, which, if it goes ahead, looks set to be boycotted by unionists.

Catalonia watchers stress the key role that previously “indy-ambivalent” or anti- independence figures of the left could play if Mr Rajoy’s crackdown continues.

Mr Sanchez is one of very few politicians to have what Catalan journalists called “sporadic” contacts with both Mr Rajoy and Carles Puigdemont, the pro-independence president of Catalonia.

So far he has backed the Conservative over Catalonia. Yesterday the Socialist leader told the Barcelona daily La Vanguardia that such support “has its limits” and called the current situation in Catalonia a “conflict”.

Referring to a show of force from Madrid – which has ordered extra police in to Catalonia – Mr Sanchez said: “We have to leave behind the law of the strongest and open the door to dialogue.”

Spain has devolved powers to its regions and “nations” – although ultra-unionists hate the latter term for places like Catalonia – since the early 1980s.

Mariano Rajoy, left, and Pedro Sanchez

HeraldScotland: epa05079278 Spanish acting Prime Minister, Mariano Rajoy (L), shakes hands with the Secretary-General of oppositor Spanish Socialist Workers' Party (PSOE), Pedro Sanchez, shortly before their first meeting held to analyse the politic scenario left by 20 D

However, Spain has never embraced federalism and its few proponents – mostly in the Catalan wing of Mr Sanchez’s party – have been squeezed in recent years.

Some 500 far-right Spanish nationalists protested at the Podemos gathering where Mr Iglesias was speaking in Zaragoza, between Madrid and Barcelona.

Reporters at the scene said bottles were thrown while one Podemos figure, Pablo Enchenique, said just a dozen police showed up to control the crowd. He was told, he tweeted, they had been sent to Catalonia to “chase ballot boxes”.

Mr Puigdemont was quick to contrast the far-right rally in Zaragoza with peaceful mass demonstrations across Catalonia.

Scots Prof in Catalan Crisis

She is, she says, just doing her “patriotic duty” and that she is no politician. But a St Andrews University academic finds herself at the centre of a one of the most tumultuous events in recent western European history.

Clara Ponsati, an economics professor, this summer took a leave of absence top serve as education minister in Catalonia’s breakaway government. It will be her job to open schools for a ballot Spain says must not take place.

She told the Sunday Times: “You cannot keep a country together against the wishes of the people but the Madrid government seems to think Catalans don’t have the right to vote - or maybe even exist.”

Analysis by David Leask: Tweety-Pie, Salvador Dali and the surreal side of Spanish unionism

It can get surreal, Catalan unionism. After all, it can count Salvador Dali among its followers.

The artist of course lived in different times when the word unionism - a recent import from these shores - would have made no sense.

There has been much talk of Francisco Franco - the 20th century fascist dictator who was feted by Dali - in and around Catalonia over the last week.

After all, the Guardia Civil - an armed paramilitary police force favoured by Franco - was used to raid buildings and arrest people organising this coming Sunday’s independence referendum.

Some commentators thought this crackdown - referred to as a “repression”, as “authoritarian” and even “totalitarian” by Catalan independence supporters - was Francoist.

But, to me, there is as much of Dali as of Franco in Spain’s brittle, legalistic attempts to stop people voting.

Salvador Dali

HeraldScotland: MASTER OF THE SURREAL: Salvador Dali

Why? Well some of the police sent Catalonia arrived on a ferry decorated with giant pictures of Looney Tunes characters, Wile E Coyote, Tweety-Pie and Daffy Duck. This is one of three floating barracks. loaded with officers, including the Guardia Civil.

Cue mockery. The Catalan independence movement may not have won over everybody in the devolved nation of 7.5m people. But, inspired by mass protests in the Baltic States in the 1990s, it has developed a campaigning flair that has helped it win friends abroad, including among Scottish nationalists.

This has included clever use of memes. One features outlines of human faces with a red stroke of paint scored across their mouths and the banner “Democracy”. Tweety-Pie - or Piolin in Catalan - has now been given that treatment.

The police may not have liked the jokes. On Sunday evening tarpaulins were hung over the side of the ship, concealing the Looney Tunes characters. That generated a new hashtag on Twitter: #freepiolin.

Tweety-Pie Protest

HeraldScotland:

The surreal vibe extends beyond cartoons. This weekend Spain’s Interior Ministry announced it would begin co-ordinating all police efforts in Catalonia to crack down on vote preparations.

That touched some Catalan nerves. Franco, after all, dissolved the force during his nearly 40-year-rule.

The front pages of Sunday papers were covered in claims that the Mossos were opposed to Madrid control. Spanish authorities denied it was a complete take-over.

Barcelona's La Vanguardia on Monday shows tarps put over Tweety-Pie

HeraldScotland:

But this is the nub of the Dali-like predicament Catalans find themselves in.

Catalonia’s parliament earlier this month by a narrow vote declared its referendum above the law of Spain.

At least that is how some in Madrid saw the decision. For some Spanish nationalists this was a “coup”. For some constitutionalists, it was a legal outrage.

Catalonia, unlike Scotland, does not have its own courts. So it can pass a referendum law. But who will enforce that law? That may depend on who can wield force on the ground, the blunt instruments of armed or riot police.

And for a 21st century democracy, that is more absurd than anything Salvador Dali dreamed up.