The mayor of London has written to Britain's home secretary, urging him to ditch planned changes to the United Kingdom's immigration policy.

Sadiq Khan says in his open letter to Sajid Javid that the proposed post-Brexit policy shows the government has not learned the lessons of the past.

The mayor, a member of the opposition Labour Party, told the Conservative Party minister that forcing long-established EU nationals to pay a 65-pound ($83) fee to apply for leave-to-remain status was wrong and likened it to the way the UK treated people from the Windrush generation who relocated to Britain from the Caribbean in the 1950s.

"The promised 'new conversation on immigration' is off to a poor start," he wrote, saying it reminded him of how some children from the Windrush generation who arrived alongside their parents were deported as adults for not having the correct visas.

"There are hundreds of thousands of young people who were born in the UK or, like the Windrush generation, brought here as young children, who are prevented from participating in the economic, social, and political life of the UK by the prohibitive cost of applying for leave-to-remain or citizenship," he wrote. "While the previous home secretary rightly waived fees for the Windrush generation, the government clearly has not learnt the wider lessons. There are many others still at risk from the same policies that led to the Windrush generation experiencing discrimination, destitution, and deportation."

Khan also attacked the Conservative Party's plans to restrict the number of people entering the UK through prioritizing skilled workers capable of earning at least 30,000 pounds ($39,000) a year, saying it would hurt London's economy by blocking people needed in industries including construction and hospitality.

Khan, who has called for a second referendum on whether or not the UK should leave the EU, said the immigration white paper published last month was a disappointment.

And he pointed out that the Home Office will likely struggle to process applications from the 3.4 million EU citizens currently residing in the UK.

"As a matter of fairness, the government should waive the settled status fee for EU nationals and their families who were resident in the UK before the referendum took place."

He said the proposed policy is one of many reasons why MPs should vote against Prime Minister Theresa May's Brexit withdrawal deal.