No you can't do this. It had never occurred to me to try such a thing, but I took a stab at it. I tried building a package with the following in the debian/control file:
Package: bzr-explorer
Architecture: all
XB-Python-Version: ${python:Versions}
Depends: ${misc:Depends}, ${python:Depends}
Recommends: tango-icon-theme
Suggests: bzr-gtk
Depends: bzr (>= 1.14), qbzr (>= 0.19)
Recommends: bzr-svn
Suggests: bzr-git
dpkg did not like it one bit:
dpkg-source: error: syntax error in bzr-explorer-1.1.2/debian/control at line 24: duplicate field Depends found
dpkg-buildpackage: error: dpkg-source --before-build bzr-explorer-1.1.2 gave error exit status 9
debuild: fatal error at line 1337:
dpkg-buildpackage -rfakeroot -d -us -uc -S failed
In fact, now that I go looking for it, this is explicitly forbidden in Debian Policy, 5.1 Syntax of control files:
A paragraph must not contain more than
one instance of a particular field
name.