How could one prepare for a telecon interview for a government lab?
10 minute job talks in the UK are pretty common. While it is not helpful. You really should have some canned talks, of various lengths between 2 minutes and 1 hour, that provide an overview of you research. For versions that are 5 minutes or less you should be able to deliver them with and without slides and the longer versions you should be able to deliver them with slides but also with a pen and napkin while sitting around a table with a few people. You never know when you will be asked to describe your research. In terms of preparation, I would focus on being able to describe your research at various levels of depth.

The best 10 minute job talks I have seen in the UK have demonstrated that the past research is important and has depth, but also has breadth in terms of fitting in with other people in the department. You do not need to be over the top in terms of saying how you fit in with the others, if you really fit in, they will see it.

I would say in terms of timing provide a 2 minute intro covering your MS, PhD and postdoc(s). That is a 30 second description of each. Ideally, the descriptions show how they fit together, and how one led to another. I would then spend another 2 minutes talking about breadth and impact; basically how your research fits I to the big picture. I would spend the remaining 6 minutes talking about a single research project. This is similar, although shorter than, a conference talk. In terms of ordering, this could come in the middle or the end.

In terms of questions. After the talk, you can expect typical research talk questions. At some point they will then switch into the formal interview. In the UK, these are scripted and they need to ask each candidate the identical questions. They have some leeway with follow up questions, but it is pretty narrow. There is often an "outsider" from HR or another department who makes sure the script is followed. The questions often focus in the essential and desirable qualities from the job description, so re-read that carefully. Brits are all about box ticking, so make sure you are able to clearly explain how you meet all the essential requirements and as many of the desirable requirements as possible.