The convenor of the pan-democratic camp, Claudia Mo, has called on people to join this afternoon's march against the extradition bill to prevent Hong Kong from being "shut down" by the mainland.
The bill will allow suspects to be surrendered to other jurisdictions - including the mainland - on a case-by-case basis. The government says it's needed to fill a legal loophole, and local courts will provide a safeguard by vetting requests. But many people - including in the pro-establishment business community - fear it could be abused by mainland authorities.
Speaking on RTHK's Letter to Hong Kong, Mo said it's obvious that the Chief Executive, Carrie Lam, is pushing the bill at the behest of Beijing, which wants to close the city as a haven for dissent.
She said: "Beijing has become increasingly impatient with Hong Kong since our umbrella movement five years ago. Zhongnanhai sees us as an unruly teenager who doesn't learn to be grateful and obedient.
"The apparent grand plan, complete with the Greater Bay Area scheme, is to assimilate Hong Kong into the vast hinterland; the idea is to - ultimately - disappear Hong Kong, or at least to change it into one of the numerous Chinese cities.
"Like a little boat, Hong Kong is sinking fast, but we're not taking this lying down, we have to put up a fight."