Remove tabs and spaces before # with sed

In order to remove leading spaces and tabs on Linux, i use following standard sed command :

cat aaa |sed 's/[ \t]*#/#/g'

but.... on AIX \t doesn't work ...

In order to run it on AIX, replace \t by Ctrl+v and tab (key tab)

cat aaaa |sed 's/^[ ]*#/#/g'