Donald Trump needs to "grow up" and stop being "abusive" to immigrants and Muslims, Labour leader Jeremy Corbyn has insisted.
In a scathing assessment of the US president-elect, Mr Corbyn accused him of exploiting the genuine anger of people who feel left behind by globalisation for his own ends.
He told BBC's Andrew Marr Show: "Donald Trump should grow up and recognise the American economy actually depends on migrant labour.
"Last year they had A Day Without Mexicans, they certainly noticed it.
"I think the treatment of Mexico by the United States, just as much as his absurd and abusive language towards Muslims, is something that has to be challenged and should be challenged,"
When Mr Corbyn, who has a Mexican wife, Laura Alvarez, was asked how he would get on with Mr Trump if he became prime minister, he said: "I'm looking forward to the conversation between my wife and Donald Trump. She is a proud Mexican."
Mr Corbyn said his wife's family felt "absolute anger and outrage" at the idea of Mr Trump building a wall along the Mexican border.
The Labour leader said immigration would come down if he was in Downing Street due to policies aimed at ending worker exploitation and wage cutting, rather than setting controls.
He added: "I think it will be lower if we deal with the issues of wage undercutting, deal with the issues of exploitation.
"I think we should also recognise that the migrants that have come to this country work.
"The migrants that come to this country contribute and pay taxes, and actually our National Health Service would simply not survive without the level of migrant labour, and migrant doctors and others, that are here, because we haven't invested enough in high skills within our own economy.
"Communities coming together to improve education, and health, and housing work better together - blaming minorities doesn't build houses."
The Labour leader accused Ukip of the same "nasty" brand of politics as France's far-right National Front, stating: "They both attempt the same shallow populist nasty appeal."
Mr Corbyn was highly critical of National Front leader Marine Le Pen, saying: "She uses awful and absurd language against Muslims in France.
"The reality is she does not have an economic answer to problems faced by left communities in France any more than Ukip has an economic answer to the left behind communities in Britain."
The Labour leader said he would not frustrate the passing of Article 50 setting in train the formal divorce deal negotiations with Brussels, but said Labour would insist on certain demands and "go behind the wire" during the negotiations to put pressure on Prime Minister Theresa May.
Mr Corbyn added: "We will respect the referendum. Therefore, there is going to be a departure from the European Union.
"We will demand that we have market access, workers' protection, consumer protection, environmental protection, justice issues through the European Court.
"We will not frustrate the bringing in of Article 50 but we will be holding the Government to account on it."