You Do Need power plug adapter while traveling from England to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in England is G. This is how they look like.

England

In England, outlets of type G are in use.

Type G

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F