Blues had been playing catch-up for most of this campaign with Charlton leading the way until recent weeks – but Birmingham have won three straight games to lead the Addicks on goal difference with just two fixtures left.
However, it looks set to go down to the wire again given Birmingham travel to Charlton on the final day (2 May, 15:00 BST).
But has missing out last season increased the pressure on Merricks’ side?
“External noise is external noise. We’re in that position because we did so well last season and we have real ambition,” she said.
“If you come to Birmingham, you have to accept that. We look for that ambition in players when we recruit because that’s what we’re about and the direction we’re moving in.
“We’re fighting for something and that’s where we want to be. We’ve said there’s no limits here. You want to win again and again.
“What that means is WSL football, then the Champions League and then you go again. It should be that in elite sports. You want to be the best, don’t you?”
Birmingham have had huge investment in recent seasons with NFL legend Tom Brady becoming a minority owner, while US-based Shelby Companies Limited purchased the women’s team in February, with ex-England and Blues star Karen Carney part of several independent investors involved in the deal.
Blues broke their club record transfer in January to sign midfielder Wilma Leidhammar, will complete the building of a new gym at the training ground this month and Merricks says they are “WSL ready”.
In contrast, rivals Charlton have one of the lowest budgets in WSL 2 and have relied on shrewd signings, as well as a strong defensive record.
They have conceded the league’s fewest goals (17), kept the most clean sheets (eight) and had a 27-game unbeaten run, which ended in March.
Charlton had opened up a nine-point lead, but three defeats in their past four matches means they still have work to do to secure promotion.
“Everyone’s fighting for everything. We are certainly fighting as well. You look at all the points, you look how tight it is at the top and at the bottom,” manager Karen Hills told BBC Sport.
“It’s just an incredible league. If you’d have told me in pre-season this is where we would be at this point in the season I’d have bitten your hand off.
“But these players deserve to be where they are. If we were to be promoted then I believe it’s probably one of the greatest achievements in my career.”
