Apparently (1) and (2) happened in the opposite order. I was relying on what Gordievsky told (quoted in a comment to the 2006 diary), but Gordievsky possibly referred to the meeting two weeks earlier:

BBC NEWS | Programmes | Panorama | How to poison a spy: Transcript

Parkes Hotel - Knightsbridge

Two weeks before, on October the 16th, staying at the Parks Hotel in Knightsbridge, Andrei Lugovoi, once a KGB officer, now a millionaire, and his friend Dimitri Kovtun, also ex-KGB. Two rooms at the hotel are later tested for Polonium. The result? Contaminated. The Polonium trail begins.

ITSU - Piccadilly

During this earlier trip Lugovoi and Kovtun meet Litvinenko for lunch in his usual place, the Itsu sushi bar in Piccadilly. The restaurant, contaminated, but not at the same seats which Scaramella and Litvinenko would use two weeks later. Could this have been the first attempt to kill him?

The Park Lane Hotel - Mayfair

October the 25th, Lugovoi returns to London and checks in at the Sheraton Park Lane Hotel. He meets Litvinenko two or three times during this trip. One hotel room at the hotel is left a radioactive mess. Today not just one room, but a whole section of the 8th floor corridor are still boarded up. Was this a second botched attempt? On October 28th Lugovoi flies back to Russia on British Airways flight GBNWX. And you've guessed it, at least one seat on the plane, contaminated. On the same day Kovtun arrives in Hamburg and sees his children, a toddler and a baby who live with his ex-wife. And they are contaminated. Lugovoi and Kovtun next meet with Litvinenko on the day he's poisoned, November the 1st.

Millennium Hotel - Mayfair

4:30 pm and the Pine Bar, the Millennium Hotel, just an hour after the sushi bar. This is when the Polonium trail gets really hot. Lugovoi and Kovtun are drinking with a third Russian, Vyacheslav Sokolenko. Business was done for the day, and they were relaxing ahead of the game. Litvinenko doesn't touch alcohol, but he'll always have a cuppa.

_{*Lunatic*, n.
One whose delusions are out of fashion.}