Two Janus Henderson-run investment trusts on Wednesday joined other British investment trusts and asked their shareholders to reject U.S. activist investor Saba Capital Management's proposal to boot out its current board and replace it with their nominees.

Saba, founded and run by star activist investor Boaz Weinstein, said last month it wanted to overhaul the boards of seven British investment trusts over performances it said ranged from "underwhelming" to "disastrous".