The express rail link connecting Hong Kong and Guangzhou in South China's Guangdong province saw a major progression on Saturday, signaling the start of the finishing work on the customs arrangements of the much-anticipated high-speed rail route.

The Hong Kong SAR government signed a co-location cooperation deal with Guangdong municipal government on Saturday, marking the start of the "three-step" process of implementing a joint checkpoint plan at Hong Kong's high-speed rail terminus.

The deal, called the Co-operation Arrangement Between the Mainland and the Hong Kong Special Administrative Region on the Establishment of the Port at the West Kowloon Station of the Guangzhou-Shenzhen-Hong Kong Express Rail Link for Implementing Co-location Arrangement, laid a legal foundation to place designated areas within the West Kowloon terminus to allow both authorities to go through customs checks at one-go.

After the signing, the SAR government and mainland will jointly seek a decision by the Standing Committee of the National People's Congress (NPCSC) in approving and endorsing the arrangement, before Hong Kong starts working on local legislation of the co-location plan.

Chief Executive Carrie Lam Cheng Yuet-ngor said while meeting the press on Saturday afternoon that she was informed that the NPCSC would deliberate the deal in December and the government would table the deal to the Legislative Council (LegCo) in February 2018 as soon as possible.

Guangdong governor Ma Xingrui (left) and Chief Executive of Hong Kong SAR Carrie Lam Cheng Yuet-ngor pose for photos after signing a deal of Co-operation Arrangement Between the Mainland and the Hong Kong Special Administrative Region on the Establishment of the Port at the West Kowloon Station of the Guangzhou-Shenzhen-Hong Kong Express Rail Link for Implementing Co-location Arrangement in Hong Kong, November 18, 2017. [Photo/Xinhua]

The plan is expected to be implemented along with the operation of the Guangzhou-Shenzhen-Hong Kong Express Rail Link (XRL) in the third quarter of 2018.

According to the deal, areas on the B2 and B3 levels, the platform areas on the B4 level and the connecting passageways, the Mainland Clearance Area and back office, the waiting hall for departing passengers, station platforms and the connecting passageways and escalators are designated as Mainland Port Area, subject to mainland laws.

Meanwhile, the compartments of trains in operation on the XRL within the area of the Hong Kong SAR (including trains which are in motion, stationary and during embarkation or disembarkation) are also regarded as part of the Mainland Port Area.

The co-location arrangement would fully unleash the transport, social and economic benefits of the Hong Kong Section of XRL, Lam said after signing the deal with Guangdong Provincial Governor Ma Xingrui on Saturday morning.

Lam also noted that the government would carefully consider views from the Legislative Council and other social sectors on implementing the plan, and take appropriate follow-up action.

Besides signing the deal, both sides also agreed to set up a port liaison and coordination mechanism to ensure "the safe, smooth and efficient operation of the Mainland Port Area and its effective regulation", and an emergency handling mechanism to assist the mainland in handling sudden or emergency incidents which may occur in the Mainland Port Area in the course of operation.