European Commission chief Jean-Claude Juncker on Wednesday urged EU nations to increase legal immigration in a bid to avoid more migrant deaths in the Mediterranean.
Juncker's comments angered his own centre-right party in the European Parliament, in Strasbourg, France, where he made the comments.
He expressed disappointment with the outcome of last week's emergency EU summit held in Brussels in the wake of the deadliest migrant shipwreck yet in the Mediterranean.
"We must work on legal immigration. If we close the doors, migrants will break in through the windows," Juncker told MEPs.
He won the support of the European parliament when he called for a quota for distributing asylum seekers across all 28 EU countries following the disaster, in which more than 700 migrants died on a boat crossing between Libya and southern Italy.
They overwhelmingly approved a resolution calling for a binding quota, by 449 votes to 130, with 93 abstentions.
But many member states will likely resist a measure requiring any revision of EU rules which require that the member state which first takes in an asylum seeker must then process their request on its soil and take responsibility for returning home those denied admission.
The last attempt to change the rules, in 2013, failed when 24 of the 28 EU member states voted against, with only Italy, Malta, Cyprus and Greece -- those now bearing the brunt of the migrant influx -- in favour.
However Juncker's appeal on immigration angered Manfred Weber, head of the conservative European Peoples Party, the largest in the European Parliament and the one Juncker belongs to.
"Whoever says that we must open the doors of the EU labour market to legal immigration is deluding himself," Weber said. "One young person out of five on our continent has no work."
The EPP blocked any reference to legal immigration in the parliament's draft resolution that was seen by AFP.
Juncker's proposal was also rejected by the European Conservatives and Reformists (ECR) as well as by the anti-EU UK Independence Party and extreme-right movements.
The European Commission, the EU executive that Juncker heads, is due May 13 to present a migration policy that will include proposals to make legal economic immigration to the EU easier, and to set refugee quotas for all member states.
It will go before EU heads of government and heads of state at their June 25-26 summit.
EU leaders announced last Thursday that they would triple monthly funding for the Triton search and rescue mission operating off southern Italy but a proposal for EU member states to provide migrant resettlement for 5,000 on a voluntary basis proved contentious.