Half a million illegal migrants will be given residency in Spain under legislation proposed by the Left-wing coalition government.

The bill, which will soon be voted on by congress, was introduced after a movement spearheaded by Regularisation Now campaigners – who have repeatedly called for illegal immigrants to be given permanent residency.

Immigration has quickly become a key concern for Spaniards after 40,000 illegal migrants arrived by sea or land in the year up mid-September – a 49 percent increase on 2023, according to Spain’s interior ministry.

The main opposition People’s Party (PP) and the far-Right Vox party have attacked Prime Minister Pedro Sánchez’s government on the issue, accusing it of operating an “open doors” policy.

Santiago Abascal, the Vox leader, said this week that Spain was suffering from an “invasion” and that he would expel all illegal immigrants if his party were to take power.

But Mr Sánchez’s government has consistently stressed the importance of a humanitarian approach to immigration, including accepting migrant boats from the Mediterranean that have already been turned away by other governments.

Yolanda Díaz, deputy prime minister and labour minister, celebrated Monday’s agreement to drive through the mass regularisation of “half a million people who live and work in our country as our neighbours”.

“Faced with racism, more rights,” Ms Díaz said.

The government’s approach to immigration has become one of the main concerns for Spaniards according to an opinion poll, with 30 per cent placing it among the country’s chief problems – almost double the result from the same survey in July.

In April, Spain’s parliament voted to accept the passage of the regularisation bill after a petition with 700,000 signatures.

Since, it has languished on the legislative back burner but is now expected to return to the floor of Congress for a formal vote after the amendment window closes this week.

Regularisation Now has described the bill as “an historic triumph”.

Spain’s immigrant population stands at just over six million, 13.5 per cent of the country’s total inhabitants.

More than a million people have benefited from previous mass regularisation processes, with the most recent and largest one giving papers to 576,000 foreigners in 2005.