How to open tabs in background?

[ghost]

How do you open tabs in the background when you singleclick to open a new page from any session? I don't want to focus on the newly opened tab everytime i click on them.

edit: Now i know you can do it with the middle mouse button but i want to change that function to the normal open behaviour not having to use the mouse wheel.

[sienori]

Middle-click a tab to open it in the background.
The option to open tabs in the background by default will be added if there are many requests.