Starting a new tab in the same window from gnome terminal

Hello,
I want to start a new tab in the same window from a gnome terminal.
I tried
gnome-terminal --tab but it opened it in the a different window.

I know that this can do by xdotool key (emulating ctrl+shift+t).
However, I also want to assign a different profile to the new tab which is
created than the default one (and this is impossible with the xdotool util).

Any advice ?
Is there a way to cause gnome-terminal --tab to create a tab in the
same window ?

regards,
DavidS