I get the following error while trying to update my repositories,

avinash@avinash-VirtualBox:~$ sudo apt-get update

sudo: unable to stat /etc/sudoers: No such file or directory

sudo: no valid sudoers sources found, quitting

sudo: unable to initialize policy plugin

It seems like I had accidentally deleted my /etc/sudoers file./etc/sudoers file was actually belongs to sudo package, so i try to reinstall sudo by pkexec but it won't work.

avinash@avinash-VirtualBox:~$ pkexec apt-get install sudo

Reading package lists... Done

Building dependency tree       

Reading state information... Done

sudo is already the newest version.

0 upgraded, 0 newly installed, 0 to remove and 301 not upgraded.

1 not fully installed or removed.

After this operation, 0 B of additional disk space will be used.

Do you want to continue [Y/n]? y

Setting up sudo (1.8.6p3-0ubuntu3.1) ...

WARNING:  /etc/sudoers not present!

chown: cannot access ‘/etc/sudoers’: No such file or directory

dpkg: error processing sudo (--configure):

 subprocess installed post-installation script returned error exit status 1

Errors were encountered while processing:

 sudo

E: Sub-process /usr/bin/dpkg returned an error code (1)

avinash@avinash-VirtualBox:~$ 

And also I had tried,

avinash@avinash-VirtualBox:~$ pkexec apt-get install --reinstall sudo

Reading package lists... Done

Building dependency tree       

Reading state information... Done

0 upgraded, 0 newly installed, 1 reinstalled, 0 to remove and 301 not upgraded.

1 not fully installed or removed.

After this operation, 0 B of additional disk space will be used.

E: Internal Error, No file name for sudo:amd64

How can i make sudo command to work again?