Looks like I got it working by running the following command:

sudo apt-get install linux-generic-lts-wily xserver-xorg-lts-wily libgl1-mesa-glx-lts-wily libglapi-mesa-lts-wily libwayland-egl1-mesa-lts-wily libgl1-mesa-glx-lts-wily:i386 libglapi-mesa-lts-wily:i386

$ glxinfo | grep OpenGL
OpenGL vendor string: Intel Open Source Technology Center
OpenGL renderer string: Mesa DRI Intel(R) Skylake Halo GT2
OpenGL core profile version string: 3.3 (Core Profile) Mesa 11.0.2
OpenGL core profile shading language version string: 3.30
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 3.0 Mesa 11.0.2
OpenGL shading language version string: 1.30
OpenGL context flags: (none)
OpenGL extensions:

Jumped the gun here.

The Nvidia driver does not work any more - get a black screen after reboot when choosing Nvidia instead of Intel.

Also there are fast video flashes on 2 way Skype video calls.

A workaround for Skype is to add the following section to /usr/share/X11/xorg.conf.d/20-intel.conf

  Section "Extensions"
    Option "XVideo" "Disable"
  EndSection

  Section "Device"

    Identifier "Intel Graphics"
    Driver "intel"
    Option "AccelMethod" "sna"
    Option "TearFree" "true"
    Option "DRI" "true"
  EndSection