When Chongqing issued new "gaokao" rules this week allowing children of migrant workers to sit the national college entrance exam in the city where their parents work, it left Zhao Tianxiang upset.

If the rule had come three years earlier, his son would have taken the college entrance exam in Chongqing, where Zhao works as a cement worker, and would be a junior in college now.

China's household restriction requires students to take the national college exam in their household registered place.

Zhao said his son was not eligible to sit gaokao in Chongqing, and could not take it in his rural home because he had spent his school years in the southeast China megacity. He was not enrolled in any schools back home.

"My son was in constant fear that he could not take the exam. The fear made him unable to concentrate on study and his grades kept on falling. In the end, we had no choice but to let him drop out," Zhao said of his son, who has also become a cement worker.

Chongqing is the latest metropolis to ease the household restriction on migrants attending gaokao, following Heilongjiang, Anhui, Jiangsu, Shandong and other provinces.

Outside the pilot regions, the exam restriction is still in place, although children of migrant workers can take the nine-year compulsory education (from elementary to high schools) without household restrictions.

Thousands of migrant employees working in Beijing, Shanghai and Guangzhou, are keeping their fingers crossed for the ban to be lifted before the coming exam season in July, so their children can take the test with their peers in the cities.

There are nearly 20 million rural children aged under 14 nationwide, who have left home with their parents to cities.

Sun Leizheng, who is from east China's Zhejiang Province and works in Chongqing, said the city's new gaokao rule is a huge relief to him.

"This means I can finally take my son with me in Chongqing. I left him studying in my home town fearing he could not take the exam in Chongqing. But the long-term separation has been distressful," said the father.

The Central Government required in August all provinces to submit plans on measures to help migrant children attend the exam before the end of the year.

Wang Boqing, president of MyCOS, a Beijing-based higher education consulting and outcome evaluation company, said that the move would definitely boost equity of schooling but was more than that.

"It's really about the rights of people. Migrant workers pay taxes and contribute to government revenues. So universities in cities where they work should be open to them, because these schools all receive funding from governments," he said.

With the year end only days away, the public is expecting concrete moves from megacities such as Beijing, Shanghai and Guangzhou, where the vast majority of migrant workers live.

However, native urbanites strongly oppose lifting the household restriction on gaokao for fear that children from "outside" will further strain educational resources in cities.

The regions that have issued new rules are mostly provinces that are home to migrant workers rather than the hotly sought-after cities that provide jobs.

Chongqing's education department predicted that children of migrant workers will only account for one percent of gaokao participants next year.

Shanghai has not given a clear date for the formation of a new gaokao rule, but the local authority said it is working on a credit-based system to ease the ban.

Under the system, children of migrant workers should get required points to qualify to attend gaokao in Shanghai. In addition to school grades, the credit also includes the number of years that their parents have worked in the city, their family property in Shanghai and years of social security payments by their families.

The Beijing municipal government reassured the public that new gaokao rules were at boardroom level, after migrant workers signed petitions and protested to local educational authorities.

Wang Boqing, the educational expert, said cities like Beijing will probably set stricter terms and conditions for gaokao eligibility and a proper threshold will be the key to the success of new rules.

"If the threshold is too high, new gaokao rules will be ineffective. If it's too low, native residents will resist because floods of children of migrant workers will affect their children's chances to enter prestigious colleges," he said.