Secretary for Constitutional and Mainland Affairs Stephen Lam Sui-lung insists the 2012 electoral reform proposal is more democratic than the 2005 package which was voted down by the Legislative Council.
Lam also claims it is more likely that the city's political system will move forward if Legco approves the reform package unveiled last week.
"We understand that universal suffrage in 2017 and 2020 is not an ideal timetable, but it is a practical one that is accepted by over 60 percent of residents," Lam told the weekly City Forum.
However, Civic Party lawmaker Audrey Eu Yuet-mee said her party will not accept any reform package that increases the number of functional constituency seats.
She described them as "regressive and unacceptable" proposals that did not move toward universal suffrage.
However, Lam said any move to scrap functional constituencies will most likely be voted down by the legislature.
Democratic Party lawmaker Emily Lau Wai-hing said her party will still continue the fight for universal suffrage in 2012.
Should that mission fail, Lau said she hoped the government can pledge a lower nomination threshold for candidates in the 2017 Chief Executive election and scrap functional constituencies by 2020.