The proposal by the Environment Bureau was speedily approved by government officials without informing Legco members. It was later explained that this happened because of an executive order made by the Exco.
According to the Basic Law, such an order comes into effect immediately it is approved, and does not need Legco approval.
When Legco lawmakers challenged such orders, Exco said there should be no restraints placed on them. Exco had the power to make such orders after Hong Kong's handover.
They are used to speeding up paperwork so government policies can come into effect earlier.
The government has bypassed Legco and the usual democratic process, and made a big decision - in this case, expanding a rubbish dump near people's homes into a country park.
This move is highly controversial because it proves that the Hong Kong government is truly executive-led (some people would call that a dictatorship) as many people suspect. Exco can bypass Legco's debates and opposition when it wants to make things happen and Legco has no power to stop it.
That means Hong Kong citizens, through their representatives in Legco, have been deprived of their right to express their opinions about what the government does, or stop it doing whatever it wants.
The so-called "constitutional crisis" refers to the government's increased use of power and its behaviour in relation to the laws of Hong Kong.