London: Britain is planning to introduce tougher rules to ensure that immigrants specially from the Indian sub-continent have a "reasonable standard" of English, Prime Minister David Cameron has said.

"Migrant families have an obligation to teach their children English before they start school. We will bring forward tougher rules to ensure those arriving in the UK have a reasonable standard of English," Cameron told the House of Commons.

According to a report, one in six children do not speak English as their first language. Ministers believe that children brought up in London stand a better chance of succeeding if their parents have a good grasp of the language.

Cameron spoke out after a Commons exchange with Yorkshire Tory MP Kris Hopkins, who said: "Sadly in Keighley, too many children start school and don't speak English."

He then asked Cameron: "Do you agree with me that there is a responsibility and an obligation upon parents to make sure their children speak English?"

Cameron replied: "I completely agree with you. The fact is, in too many cases this isn't happening.

"The last government did make some progress on making sure people learned English when they came to our country. I think we need to go further. If you look at the figures for the number of people who are brought over as husbands and wives, particularly from the Indian sub-continent, we should be putting in place and we will be putting in place tougher rules to make sure they do learn English so when they come, if they come, they can be more integrated into our country."

A recent study by MigrationWatch found that children who speak English as their first language are in a minority in some inner-city London schools.

According to a report in the Daily Mail, Birmingham, Bradford and Leicester all have more than 40 per cent of pupils in primary schools who do not have English as a first language.

To date, the government's policies have focused upon marriage visas. Since September, those coming to Britain to marry UK citizens have been forced to sit pre-entry tests proving a basic level of English.

Lawyers argue that the tests, which apply only to those from non-English-speaking countries, are discriminatory, and breach human rights law. But Immigration Minister Damian Green argued that the English language requirement would allow for a "more cohesive society".