upgrade - QGIS on 14.04 packages have unmet dependencies

I have got a problem with my QGIS on a trusty 14.04.01.
After upgrading my machine from precise 12.04 to trusty 14.04, QGIS was disappeared from the available software.
I have autoremoved it and removed the PPAs from the source.list as instructed here successfully.
However, when I try to run the new sudo apt-get install QGIS I am getting the following dependency errors and I kinda stuck here.

I run pgres 9.3 and postGIS 2.2 without any problem but when I try to install Qgis I fail all the time.

Any thoughts or a workaround will be appreciated!

On

Distributor ID: Ubuntu
Description:    Ubuntu 14.04.1 LTS
Release:    14.04
Codename:   trusty

The error:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created

or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies.
 qgis : Depends: libgdal1h (>= 1.9.0) but it is not going to be installed
        Depends: libqgis-analysis2.4.0 but it is not going to be installed
        Depends: libqgis-core2.4.0 but it is not going to be installed
        Depends: libqgis-gui2.4.0 but it is not going to be installed
        Depends: libqgis-networkanalysis2.4.0 but it is not going to be installed
        Depends: qgis-providers (= 2.4.0-0trusty3) but it is not going to be installed

        Recommends: qgis-plugin-grass but it is not going to be installed
        Recommends: qgis-plugin-globe but it is not going to be installed
        Recommends: python-qgis but it is not going to be installed
E: Unable to correct problems, you have held broken packages.`

My sources.list

# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.

deb http://gb.archive.ubuntu.com/ubuntu/ trusty main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty main restricted

## Major bug fix updates produced after the final release of the
## distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates main restricted

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any

## review or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty universe
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates universe
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates universe

## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu 
## team, and may not be under a free licence. Please satisfy yourself as to 
## your rights to use the software. Also, please note that software in 
## multiverse WILL NOT receive any review or updates from the Ubuntu

## security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty multiverse
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates multiverse

## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review

## or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse

deb http://security.ubuntu.com/ubuntu trusty-security main restricted
deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted
deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe
deb http://security.ubuntu.com/ubuntu trusty-security multiverse
deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse


## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
# deb http://archive.canonical.com/ubuntu precise partner
# deb-src http://archive.canonical.com/ubuntu precise partner

## This software is not part of Ubuntu, but is offered by third-party
## developers who want to ship their latest software.

# deb http://extras.ubuntu.com/ubuntu trusty main
deb-src http://extras.ubuntu.com/ubuntu trusty main
deb http://archive.canonical.com/ trusty partner
deb-src http://archive.canonical.com/ trusty partner
deb http://apt.postgresql.org/pub/repos/apt/ precise-pgdg main # disabled on upgrade to trusty
#add qgis

It took me a while to figure out what went wrong. You will see it in the last line of my sources.list.
Therefore, if you have got the same problem as me then what you need to do is to follow this wiki.

Then, you will have to make sure that all the ubuntugis or qgis dependencies from the etc/apt/sources.list.d are removed. The code will look like sudo rm /etc/apt/sources.list.d/ thegisfile

Finally, follow the instructions to install QGIS from here and you are done!