I received a reply from BAS and they have confirmed that they still maintain the 32-million-year timeframe. As I partially suspected, the journalist appears to have made an incorrect assumption and erroneously drew contrasts between the two dates:
"Antarctica's ice sheet formed about 32million years ago but Jordan said that experts NOW believed the oldest ice was only 1.4million years old."
Correct statement should perhaps have been:
Antarctica's ice sheet formed about 32million years ago and Jordan said that experts believed the oldest ice was only 1.4million years old.
To clarify, the oldest dating of the ice via an ice core is 800,000 years. Theoretically, the oldest remaining ice is 1.4 million years based on the current rate of ice flow.
The ice sheet, on the other hand, is believed to have originated 32 mya with more than 30 million years of ice having been shed from the sheet as it flows out beyond the continent and cleaves free.
According to Tom Jordan's response, the 32 million figure has been established by the following:
"Firstly glacial drop stones found far out in the ocean, which can only have been carried by icebergs. These are dated using the micro-fossils found with them.
Secondly there is a change in the isotopic composition of the oceans recorded in fossil shells, indicating lots of water was locked away in an ice sheet.
Thirdly there was a global drop in sea level, related to storage of a large volume of ice on the continents."