The populist leader vowing to “make Spain great again” has been axed from the only televised debate confirmed ahead of the election later this month.

The Atresmedia network was ordered to drop Vox leader Santiago Abascal from its debate after Spain’s Central Election Board ruled his appearance would not be “proportional” to votes cast for the party at elections in 2015, when the then only recently formed party failed to win representation in the national parliament.

Since then however, Vox has enjoyed a huge political breakthrough, becoming the third largest party at elections in Andalucia in December when it gained 11 per cent of the vote and 12 seats — far outperforming predictions it would win just five seats.

Now the party faces being excluded from an election debate for a vote where some polls predict they could finish in third place nationally, potentially becoming an important faction in the Spanish parliament and even a player in a future coalition government.

On Twitter, the party blasted the decision as an example of institutional bias against patriotic parties, asserting that it was made by “the same electoral board that greenlighted [left-wing political parties] Podemos and Ciudadanos when they had no representation”.

Shortly after, Abascal stated that the left “no longer hides” its intention to destroy the conservative party, tweeting: “First [the establishment] tried to manipulate our message in the media, then they sent the hooded vanguard of [Antifa activists] to attack us physically, and now they censor us to prevent Spaniards from hearing us”.

“It’s clear who calls the shots still in Spain: the separatists. Until April 28. Because a great victory for #LongLiveSpain will see those parties who wish to destroy our co-existence, constitution and homeland banned,” he added.

While Atresmedia agreed to respect the ruling, “readapting the format of its debate” to include only the leaders of the Socialist Workers’ Party, the centre-right liberal Popular Party, far-left Podemos, and the globalist Ciudadanos, the private network said it would appeal against the decision.

“Atresmedia maintains that a debate between five candidates is of the greatest journalistic value and most relevance for voters,” the network said in a statement.

Vox, which earlier this year celebrated the anniversary of the Spanish Reconquista, has gained momentum over the last year presenting itself as the only socially conservative, anti-mass migration, and pro-tradition force in a political field where parties supposedly on the right are liberal on social issues.

In the face of increasingly aggressive identity politics from the left, with activists and liberals determined to impose so-called gender ideology on children and to erase Christianity from public spaces, Abascal has pledged to defend Spain against the “ideological battle” waged by progressives.