Manchester United defender Wes Brown admits they're aware of the growing threat of Manchester City.

But Brown insists they're not about to roll over ahead of their Carling Cup semifinal.

"You are aware of the shifts in power but we have always been up there, which is a good achievement," Brown told Inside United. "We set out to challenge for the title at the start of every season and to continue doing that we have to keep working hard.

"City have got a lot of money to spend and have therefore bought good players and will probably continue to do so. That means they are going to be challenging - they have to be with the players they have.

"We have just got to keep doing what we are doing, continue improving and hopefully we can keep on doing as well as we have over the last few years."