The Chief Executive was urged yesterday to explain whether he knew what his aide Andrew Lo Cheung-on was doing when Mr Lo met a university researcher to discuss opinion polls on Mr Tung's popularity. On Thursday, Timothy Wong Ka-ying of the Chinese University's Institute of Asia-Pacific Studies, said Mr Lo had made suggestions about how to improve the polls to 'make them more objective and scientific'. Democratic Party chairman Martin Lee Chu-ming questioned why this had become a matter of concern for the Chief Executive's Office. He said the way Mr Lo sought a meeting with Hong Kong University vice-chancellor Professor Cheng Yiu-chung amounted to political pressure. An independent committee - appointed by the Chief Executive under law with the power to summon people to testify - should conduct the inquiry into the issue, he said. 'The issue is no longer the university's internal affair, the inquiry should not be left to an internal commission.' Fellow Democrat James To Kun-sun, also a court member of the university, said Mr Lo's meeting with Professor Cheng amounted to political pressure. Emily Lau Wai-hing, of The Frontier, said Mr Lo's move was clearly an intervention into academic freedom. 'It would be ridiculous for the Chief Executive not to know what his aide was doing. Mr Tung should explain,' Ms Lau said. Liberal Party chief James Tien Pei-chun said Mr Lo should give an account of whether his views and questions were his own or represented those of Mr Tung. Tsang Yok-sing, chairman of the Democratic Alliance for the Betterment of Hong Kong, said the key issue was whether Mr Lo passed a message to stop pollster Dr Robert Chung Ting-yiu's surveys. 'There is no evidence that Mr Lo had any intention to do so,' Mr Tsang said. Non-affiliated former lawmaker Andrew Wong Wang-fat dismissed students' appeals for Mr Tung to ask ex-legislators to return for an emergency Legco session to set up an independent commission to look into the matter.